Scotland
From LoveToKnow 1911
SCOTLAND, the name given in modern times to that portion of Great Britain which lies north of the English boundary; it also comprises the Outer and Inner Hebrides and other islands off the west coast, and the Orkney and Shetland islands off the north coast. With England lying to the south, it is thus bounded on the N. and W. by the Atlantic Ocean, and on the E. by the North Sea. It is separated from England by the Solway Firth, the Sark, Scotsdyke (an old embankment in 55°3' N., connecting the Sark with the Esk), the Esk (for one mile), the Liddel, the Kershope, the Cheviot Hills, the Tweed and a small area known as the " liberties " of Berwick. The mainland lies between 58° 40' 30" (at Dunnet Head in Caithness) and 54° 38' N. (Mull of Galloway in Wigtownshire), and 1° 45' 32" (Buchan Ness in Aberdeenshire) and 6° 14' W. (Ardnamurchan Point in Argyllshire). Including the islands, however, the extreme latitude north is 60° 51' 30" (Out Stack in the Shetlands) and the extreme longitude west 8° 35' 30" (St Kilda). The greatest length from Cape Wrath in Sutherland to the Mull of Galloway is 274 m., and the greatest breadth from Buchan Ness to Applecross in the shire of Ross and Cromarty 154 m., but from Bonar Bridge at the head of Dornoch Firth to the head of Loch Broom it is only 26 m. wide, and 30 m. from Grangemouth on the Forth to Bowling on the Clyde. The coast-line is estimated at 2300 m., the arms of the sea being so numerous and in several cases penetrating so far inland that few places are beyond 40 m. from salt water. The total area is 19,069,500 acres or 29,796 sq. m., exclusive of inland waters (about 608 sq. m.), the foreshore (about 498 sq. m.) and tidal water (about 608 sq. m.).
The name Scotland for this geographical area of northern Britain (the Caledonia of the ancients - a name still poetically used for Scotland) originated in the 11th century, when (from the tribe of Scots) part of it was called Scotia (a name previously applied to what is now Ireland); and the name of Scotland became established in the 12th and 13th centuries. The name of Britain or North Britain is still firmly associated with Scotland; thus English letters are generally addressed, e.g. "Edinburgh, N.B.," i.e. North Britain; and Scottish people have long objected to the conventional use south of the Tweed of the word " English," when it really means (as they correctly, but sometimes rather pedantically, insist) " British."
I. Geography
Physically, Scotland is divided into three geographical regions - the " Highlands " (subdivided by Glen More into the NorthWestern and South-Eastern Highlands); the Central Plain or " Lowlands " (a tract of south-westerly to north-easterly trend, between a line drawn roughly from Girvan to Dunbar and a line drawn from Dumbarton to Stonehaven); and the Southern Uplands.
Regions
The Highlands
Nearly all this region is lofty ground, deeply trenched with valleys and sea lochs. The only considerable lowlying area embraces the eastern part of Aberdeenshire and the northern parts of Banff, Elgin and Nairn - tracts which, ethnologically, do not fall within Highland territory. Along both sides of the Moray Firth a strip of level land lies between the foot of the hills and the sea, while the county of Caithness, occupying a wide plain, does not, strictly speaking, belong to the Highlands. Seen from Strathmore or the Firth of Clyde the Highlands present well-defined masses of hills abruptly rising from the Lowland plains, and from any of the western islands their sea front resembles a vast rampart indented by lochs and rising to a uniform level, which sinking here and there allows glimpses of still higher summits in the interior. The Highland hills differ from a mountain chain such as the Alps not merely in their inferior elevation but in configuration and structure. They are made up of a succession of more or less parallel confluent ridges, having in the main a trend from north-east to south-west. These ridges are separated by longitudinal and furrowed by transverse valleys. The portions of the ridge thus isolated rise into what are regarded as mountains, though they are really only loftier parts of the ridge, along which indeed the geological structure is continued. It is remarkable how the average level of the summits is maintained. Viewed from near at hand a mountain may seem to tower above the surrounding country, but from a distance it will be seen not to rise much above the general uniformity of elevation. There are no gigantic dominant masses obviously due to special terrestrial disturbance. A few apparent exceptions occur along the western seaboard of Sutherland, in Skye and elsewhere, but examination of their structure at once explains the reason of their prominence and confirms the rule. The surface of the Highlands is rugged. The rocks project in innumerable bosses and crags, which roughen the sides and crests of the ridges. The shape and colour of these roughnesses depend on the nature of the underlying rock. Where it is hard and jointed, weathering into large quadrangular blocks, the hills are more especially distinguished for the gnarled bossy character of their declivities, as may be seen in Ben Ledi and the heights to the north-east of it. Where, on the other hand, the rock decays with smaller debris, the hills assume smoother contours, as in the slate hills running from the Kyles of Bute to Loch Lomond. But, regarded broadly, the Highland mountains are monuments of erosion, the relic of an old tableland, the upper surface and former inclinations of which are shown approximately by the summits of the existing masses and the direction of the chief water-flows.
The Highlands are separated into two completely disconnected and in some respects contrasted regions by the depression of the Great Glen, extending from Loch Linnhe to Inverness, by which the ancient plateau was severed. In the north-western section the highest ground is found along the Atlantic coast, mounting steeply from the sea to an average height of 2000 to 3000 ft. The watershed consequently keeps close to the western seaboard, and indeed in some places is not above a mile and a half from the shore. From these hills which catch the first downpour of the rains from the ocean, the ground falls eastward. Numerous eminences, however, prolong the mountainous features to the North Sea and south-eastward to Glen More. The difference of the general level on the two sides of the water-parting is reflected in the length of their streams. On the west the drainage empties itself into the Atlantic after flowing only a very few miles, on the east it has to run 30 or 40 m. At the head of Loch Nevis the western stream is but 3 m. long, while the eastern has a course of some 18 m. to the Great Glen. Throughout the northwestern region uniformity of features characterizes the scenery, betokening even at a distance the general monotony of structure. But the sameness is relieved along the western coast of the shires of Sutherland and Ross and Cromarty by groups of cones and stacks, and farther south by the terraced plateaus and abru p t conical hills of Skye, Rum and Mull.
The south-eastern region of the Highlands, having a more diversified geological structure, offers greater variety of scenery. Most of the valleys, lakes and sea lochs run in a south-westerly and northeasterly direction, a feature strikingly exhibited in west Argyllshire. But there are also several important transverse valleys, those of the Garry and Tay being the most conspicuous examples. The watershed, too, is somewhat different. It first strikes eastwards round the head of Loch Laggan and then swings southwards, pursuing a sinuous course till it leaves the Highlands on the east side of Loch Lomond. The streams flowing westward, however, are still short, while those running to the north-east, east and south-east have long courses and drain wide areas. There is a marked contrast between the configuration of the north-eastern district and the other parts of this region. In that area the Grampians rise into wide flat-topped heights or moors often more than 3000, and in a few places exceeding 4000 ft. in height, and bounded by steep declivities and sometimes by precipices. Seen from an eminence on their surface, the inference is irresistible that these plateaus are fragments of the original tableland, trenched into segments by the formation of the longitudinal and transverse valleys. Farther to the south-west, in the shires of Perth, Inverness and Argyll, they give place to the ordinary hummocky crested ridges of Highland scenery, which, however, in Ben Nevis and Aonach Beg reach a height of over 4000 ft.
Besides the principal tracts of low-lying ground in the Highlands already alluded to, there occur long narrow strips of flat land in the more important valleys. Most of the straths and glens have a floor of detritus which, spread out between the bases of the boundary hills, has been levelled into meadow land by the rivers and provides almost the sole arable ground in each district.
The Lowlands
The Lowlands of Mid-Scotland, or the Central Plain, constitute a broad depression with south-westerly to north-easterly trend lying between the Highland line that runs from the head of the Firth of Clyde to Stonehaven and the pastoral uplands that stretch from Girvan to Dunbar. They may be regarded as a long trough of younger rocks let down by parallel dislocations between the older masses to the south and north. The lowest of these younger rocks are the various sedimentary and volcanic members of the Old Red Sandstone. These are covered by the successive formations of the Carboniferous system. The total thickness of both these groups of rock cannot be less than 30,000 ft., and, as most of them bear evidence of having been deposited in shallow water, they could only have been accumulated during a prolonged period of depression. The question arises whether this depression affected only the area of the midland valley, or extended also to the regions to the north and south; and so far as the evidence goes there is ground for the inference that, while the depression had its maximum along the line of the lowlands, it also involved some portion at least of the high grounds on either side. In other words, the Old Red Sandstone and Carboniferous rocks, though chiefly accumulated in the broad lowland valley, crept also over some part of the hills on either side, where a few outliers tell of their former extension. The central Lowlands are thus of great geological antiquity. During and since the deposition of the rocks that underlie them the tract has been the scene of repeated terrestrial disturbances. Long dislocations have sharply defined its northern and southern margins. By other fractures and unequal movements of upheaval or depression portions of the older rocks have been brought up within the bounds of the younger, and areas of the younger have been enclosed by the older. On the whole, these disturbances have followed the prevalent north-easterly trend, and hence a general tendency may be observed among the main ridges and valleys to run in that direction. The chains of the Ochil, Sidlaw, Pentland, Renfrew, Campsie and Fintry Hills, and the valleys of the Strathmore, Firth of Tay, and the basin of Midlothian may be cited as examples. But the dominant cause in the determination of the topographical prominences and depressions of the district has been the relative hardness and softness of the rocks. Almost all the eminences in the Lowlands consist of hard igneous rocks, forming not only chains of hills such as those just mentioned and others in Ayrshire and Lanarkshire, but isolated crags and hills like those on which stand the castles of Edinburgh and Stirling, and others conspicuous in the scenery of Fife and the Lothians.
Of the three chief valleys in the central Lowlands two, those of the Tay and the Forth, descend from the Highlands, and one, that of the Clyde, from the Southern Uplands. Though on the whole transverse, these depressions furnish another notable example of that independence of geological structure already referred to.
The Southern Uplands
The Southern Uplands extend from the North Channel in the southwest to St Abb's Head in the north-east and form a well-defined belt of hilly ground, and though much less elevated (their highest point is 2764 ft. above the sea) than the Highlands, rise with scarcely less abruptness above the lower tracts that bound them. Their northwestern margin for the most part springs boldly above the fields and moorlands of the Central Plain, and its boundary for long distances continues remarkably straight. On the south and south-east their limits in general are less prominently defined, but are better seen west and south-west of the Nith from which they extend to the sea and Loch Ryan, terminating in the extreme south-west in a plateau of which the loftiest point is little over woo ft. above the sea. The Cheviots do not properly belong to the Uplands, from which they are separated by Liddesdale and other hollows and on which they abut abruptly. But though geologically the one set of mountains must be separated from the other, geographically it is convenient to include within the Southern Uplands the whole area between the Central Plain and the Border. A survey of the Uplands, therefore, presents in succession from south-west to north-east the Kirkcudbrightshire and Ayrshire mountain moors, the Lowthers, the Moffat hills, the Moorfoots and the Lammermuirs. Distinguished especially by the smoothness of their surface, they may be regarded as a roiling tableland or moorland, traversed by many valleys conducting the drainage to the sea. This character is well observed from the heights of Tweedsmuir. Wide, mossy moors, 2000 ft. or more above the sea, and sometimes level as a racecourse, spread out on all sides. Their continuity, however, is interrupted by numerous valleys separating them into detached flat-topped hills, which are comparatively seldom marked by precipices of naked rock. Where the rock projects it more usually appears in low crags and knolls, from which long trails of grey or purple debris descend till they are lost among the grass. Hence, besides being smooth, the uplands are remarkably verdant. They form indeed excellent pasture-land, while the alluvial flats in the valleys and even some of the lower slopes are fitted for grain and green crops.
This uniformity of aspect is doubtless traceable to the prevalence of the same kind of rocks and the same geological structure. The Silurian greywackes and shales that underlie almost the whole of the Uplands weather generally into small angular debris, and at a tolerably uniform rate of disintegration. But slight differences may readily be detected even where no feature interferes noticeably with the monotony. The bands of massive grit and coarse greywacke, for example, break up into larger blocks and from their greater hardness are apt to project above the general surface of the other softer rocks. Hence their line of trend, which like that of all the other strata is in a north-easterly direction, may be traced from hill to hill by their more craggy contours. Only in the higher tracts are there rugged features recalling the more savage character of Highland scenery. In the heights of Harden (2651 ft.) and Whitecoomb (2695), whence the Clyde, Tweed, Annan, and Moffat Water descend, the high moorlands have been scarped into gloomy corries, with crags and talus-slopes, which form a series of landscapes all the more striking from the abrupt and unexpected contrast which they offer to everything around them. In Galloway, also, the highest portions of the Uplands have acquired a ruggedness and wildness more like those of the Highlands than an y other district in the south of Scotland. For this, however, there is an obvious geological reason. In that region the Silurian rocks have been invaded by large bosses of granite and have undergone a variable amount of metamorphism which has in some places altered them into hard crystalline schists. These various rocky masses, presenting great differences in their powers of resisting decay, have yielded unequally to disintegration: the harder portions project in rocky knolls, crags and cliffs, while the softer parts have been worn down into more flowing outlines. The highest summit in the south of Scotland - Merrick (2764 ft.) - consists of Silurian strata much altered by proximity to the granite, while the rest of the more prominent heights (all in Kirkcudbrightshire) - Rinns of Kells (2668 ft.), Cairnsmuir of Carsphairn (2612), and Cairnsmore of Fleet (2331) - are formed of granite.
The watershed of the Southern Uplands is of much interest in relation to their geological history. It runs from the mouth of Loch Ryan in a sinuous north-easterly direction, keeping near the northern limit of the region till it reaches the basin of the Nith, where it quits the Uplands altogether, descends into the lowlands of Ayrshire, and, after circling round the headwaters of the Nith, strikes south-eastwards across half the breadth of the Uplands, then sweeps north and eastwards between the basins of the Clyde, Tweed and Annan, and then through the moors that surround. the sources of the Ettrick, Teviot and Jed, into the Cheviot Hills. Here again the longest slope is on the east side, where the Tweed bears the whole drainage of that side into the sea. Although the rocks throughout the Southern Uplands have a persistent northeasterly and south-westerly strike, and though this trend is apparent in the bands of more rugged hills that mark the outcrop of hard grits and greywackes, nevertheless geological structure has been much less effective in determining the lines of ridge and valley than in the Highlands. On the southern side of the watershed, in Dumfriesshire and Galloway, the valleys run generally transversely from north-west to south-east. But in the eastern half of the Uplands. the valleys do not appear to have any relation to the geological structure of the ground underneath.
Characteristic Features
Though Scotland is pre-eminently land of mountain and of flood," yet its leading physical features are not the lofty ridges carved out of the primeval plateau Valleys. - apparently the dominant characteristic - but the valleys which have been opened through them by the agencies of water and weather, and which are therefore its fundamental topographical element. The longitudinal valleys, which run in the same general direction as the ridges - that is, north-east and south-west--have had their trend defined by geological structure, such as a line of dislocation (the Great Glen), or the plications of the rocks (Lochs Ericht, Tay and Awe, and most of the sea lochs of Argyllshire). The transverse valleys run north-west or south-east and are for the most part independent of geological structure. The valley of the Garry and Tay crosses the strike of all the Highland rocks, traverses the great fault on the Highland border, and finally breaks through the chain of the Sidlaw Hills at Perth. The valley of the Clyde crosses. the strike of the Silurian folds in the Southern Uplands, the boundary fault, and the ridges of the Old Red Sandstone, and pursues its northwesterly course across the abundant and often powerful dislocations of the Carboniferous system.
The crumpling of the earth's crust which folded the rocks of the Highlands and Southern Uplands probably upraised above the sea a series of longitudinal ridges having a general north-easterly direction. The earliest rain that fell upon these ridges would run off them, first in transverse watercourses down each short slope, and then in longitudinal depressions wherever such had been formed during the terrestrial disturbance. Afterwards the pathways of the streams would be gradually deepened and widened into valleys. Hence the valleys are of higher antiquity than the mountains that flank them. The mountains in fact have been hewn out of the original bulk of the land in proportion as the valleys have been excavated_ The denudation would continue so long as the ground stood above the level of the sea; but there have been prolonged periods of depression, when the ground, instead of being eroded, lay below the sea-level and was buried sometimes under thousands of feet of accumulated sediment, which completely filled up and obliterated the previous drainage-lines. When the land reappeared a new series of valleys would at once begin to be eroded; and the subsequent degradation of these overlying sediments might reveal portions of the older topography, as in the case of the Great Glen, Lauderdale, and other ancient valleys. But the new drainage-lines have usually little or no reference to the old ones. Determined by the inequalities of surface of the overlying mantle of sedimentary material, they would be wholly independent of the geological structure of the rocks lying. below that mantle. Slowly sinking deeper and deeper into the land, they might eventually reach the older rocks, but they would keep in these the lines of valley that they had followed in the overlying deposits. In process of time the whole of these deposits might be denuded from the area, and there might even remain no trace of the younger formations on which the valleys began and which guided their excavation. This is probably the explanation of the striking independence of geological structure exhibited by the Tweed and the Nith.
Among the valleys certain prevailing characteristics have been recognized in their popular names. Straths are broad expanses of low ground between bounding hills and are usually traversed by one main stream and its tributaries - e.g. Strath Tay, Strath Spey, Strath Conon. This name, however, has also been applied to wide tracts of lowland which embrace portions of several valleys, but are defined by lines of heights on each side; the best example is afforded by Strathmore - the " Great Strath " - between the southern margin of the Highlands and the line of the Sidlaw Hills. This long and wide depression, though it looks like one great valley, strictly speaking, includes portions of the valleys of the Tay, Isla, North Esk and South Esk, all of which cross it. Elsewhere in central Scotland such a wide depression is known as a howe, as in the Howe of Fife between the Ochil and Lomond Hills. A glen is a narrower and steeper-sided valley than a strath, though the names have not always been applied with discrimination. Most of the Highland valleys are true glens, Glencoe being the best-known example. The hills rise rapidly on each side, sometimes in grassy slopes, sometimes in rocky bosses and precipitous cliffs, while the bottom is occupied by a lake. In the south of Scotland the larger streams flow in wide open valleys called dales, as in Clydesdale, Tweeddale, Teviotdale, Liddesdale, Eskdale, Nithsdale. The strips of alluvial land bordering a river are known as haughs, and where in estuaries they expand into wide plains they are termed carses. The carses of the Forth extend seawards as far as Bo'ness and consist chiefly of raised beaches. The Carse of Gowrie is the strip of low ground intervening between the Firth of Tay and the Sidlaw Hills. Brae signifies the steep bank of a river, and so any slope or hill-side.
River-gorges are characteristic features in many of the valleys. In the Old Red Sandstone they are particularly prominent where River- that formation has lain in the pathway of the streams. sweeping down from the Highlands. In the basin of the gorges Moray Firth some fine examples may be seen on the Nairn and Findhorn, while on the west side of the Cromarty Firth some of the small streams descending from the high grounds of the east of the shire of Ross and Cromarty have cut out defiles in the Conglomerates, remarkable for their depth and narrowness. Towards the south margin of the Highlands notable instances of true canyons in the Old Red Sandstone are to be seen where the Isla and North Esk enter that formation. The well-known gorge in which the Falls of Clyde are situated is the best example in the Lowlands. (For the chief rivers see the separate articles on them, and also the section on the physical features in the article on the different shires of Scotland.) The topography of the country being the result of prolonged denudation, it is reasonable to infer that the oldest surfaces likely to be preserved are portions of some of the platforms of erosion successively established by the wearing down of the land to the sea-level. Relics of these platforms occur both in the Highlands and among the Southern Uplands. Allusion has already been made to the flat-topped moorlands which in the eastern Grampians reach heights of 3000 to 4000 ft. above the sea. The most familiar example perhaps is the top of Lochnagar, where, at the level of 3500 ft., the traveller finds himself on a broad undulating moor, more than a mile and a half long, sloping gently towards Glen Muick and terminating on the north in a range of granite precipices. The top of Ben Macdhui stands upon nearly a square mile of moor exceeding 4000 ft. in elevation. These mountains lie within granite areas; but not less striking examples may be found among the schists. The mountains at the head of Glen Clova and Glen Isla, for instance, sweep upwards into a broad moor some 3000 ft. above the sea, the more prominent parts of which have received special names - Driesh, Mayar, Tom Buidhe, Tolmount, Cairn na Glasha. It would hardly be an exaggeration to say that there is more level ground on the tops of these mountains than in areas of corresponding size in the valleys below. That these high plateaus are planes of erosion is shown by their independence of geological structure, the upturned edges of the vertical and contorted schists having been abruptly shorn off and the granite having been wasted and levelled along its exposed surface. Among the Southern Uplands exist traces of a similar tableland of erosion. The top of Broad Law on the confines of Peeblesshire and Selkirkshire, for example, is a level moor comprising between 300 and 400 acres above the contour line of 2500 ft. and lying upon the upturned edges of the greatly denuded Silurian grits and shales. An instructive example of the similar destruction of a much younger platform is to be found in the terraced plateaus of Skye, Eigg, Canna, Muck, Mull and Morven, which are portions of what was probably originally a continuous plain of basalt. Though dating back only to older Tertiary time, this plain has been so deeply trenched by the forces of denudation that it has been reduced to mere scattered fragments. Thousands of feet of basalt have been worn away from many parts of its surface; deep and wide valleys have been carved out of it; and so enormously has it been wasted, that it has been almost entirely stripped from wide tracts which it formerly covered and where only scattered outliers remain to prove that it once existed.
It is curious that broad flat-topped mountains are chiefly to be found in the eastern parts of the country. Traced westwards, these forms gradually give place to narrow ridges and crests. No contrast, for instance, can be greater than that between the wide elevated moors of the eastern Grampians, and the crested ridges of western Inverness-shire and Argyllshire - Loch Hourn, Glen Nevis, Glencoe - or that between the broad uplands of Peeblesshire and the precipitous heights of Galloway. Geological structure alone will not account for these contrasts. Perhaps the cause is to be sought mainly in differences of rainfall. The western mountains, exposed to the fierce lash of the Atlantic rains, sustain the heaviest and most constant precipitation. Their sides are seamed with torrents which tear down the solid rock and sweep its detritus into the glens and sea lochs. The eastern heights,on the other hand,experience a smaller rainfall and consequently a diminished rate of erosion. No doubt, too, the preponderance of rainfall in the west has persisted for an enormous period.
Regarding the existing flat-topped heights among the eastern Grampians as remnants of what was once the general character of the surface, we can trace every step in the gradual obliteration of the tableland and in the formation of the most rugged and most individualized forms of isolated mountain. In fact, in journeying westwards across the tops of the Highland mountains we pass, as it were, over successive stages in the history of the origin of Highland scenery. The oldest types of form lie on the east side and the newest on the west. From the larger fragments of the denuded tableland we advance to ridges with narrow tops, which pass by degrees into sharp rugged crests. The ridges, too, are more and more trenched until they become groups of detached hills or mountains. In the progress of this erosion full scope has been afforded for the modification of form by variation in geological structure. Each ridge and mountain has been cut into its shape by denudation, but its outlines have been determined by the nature of the rocks and the manner in which they have yielded to decay. Every distinct variety of rock has impressed its own character upon the landscape. Hence, amid the monotonous succession of ridge beyond ridge and valley after valley, diversity of detail has resulted from the varying composition and grouping of the rocks.
The process by which the ancient tablelands have been trenched into valleys and confluent ridges is most instructively displayed among the higher mountains, where erosion proceeds at an accelerated pace. The long screes or talus-slopes at the foot of every crag and cliff bear witness to the continual waste. The headwaters of a river cut into the slopes of the parent hill. Each valley is consequently lengthened at the expense of the mountain from which it descends. Where a number of small torrents converge in a steep mountain recess, they cut out a crescent-shaped hollow or halfcauldron, which in the Scottish Highlands is known as a corrie. It is doubtful whether the convergent action of the streams has been the sole agency in the erosion of these striking cavities, or whether snow and glacier-ice have had a share in the work. No feature in Highland scenery is more characteristic than the corries, and in none can the influence of geological structure be better understood. Usually the upper part of a corrie is formed by a crescent of naked rock, from which long trails of debris descend to the bottom of the hollow. Every distinct variety of rock has its own type of corrie, the peculiarities being marked both in the details of the upper cliffs and crags, and in the amount, form and colour of the screes. The Scottish corries have been occupied by glaciers. Hence their bottoms are generally ice-worn or strewn over with moraine stuff. Sometimes a small tarn fills up the bottom, ponded back by a moraine. It is in such localities that we can best observe the last relics of the glaciers that once overspread the country. Among these high grounds also the gradual narrowing of ridges into sharp, narrow, knife-edged crests and the lowering of these into cols or passes can be admirably studied. Where two glens begin opposite to each other on the same ridge, their corries are gradually cut back until only a sharp crest separates them. This crest, attacked on each front and along the summit, is lowered with comparative rapidity, until merely a low col or pass may separate the heads of the two glens. The various stages in this kind of demolition are best seen where the underlying rock is of granite or similarly tough material, which at the same time is apt to be split and splintered by means of its numerous transverse joints. The granite mountains of Arran furnish excellent illustrations.
Where a rock yields to weather with considerable uniformity in all directions it is likely to assume conical forms in the progress of denudation. Sometimes this uniformity is attained by a general disintegration of the rock into fine debris, which rolls down the slopes in long screes. In other cases it is secured by the intersection of joints, whereby a rock, in itself hard and durable, is divided into small angular blocks, which are separated by the action of the elements and slide down the declivities. In many instances the beginning of the formation of a cone may be detected on ridges which have been deeply trenched by valleys. The smaller isolated portions, attacked on all sides, have broken up under weather. Layer after layer has been stripped from their sides, and the flat or rounded top has been narrowed until it has now become the apex of a cone. The mountain Schiehallion (3547 ft.) is an instance of a cone not yet freed from its parent ridge. Occasionally a ridge has been carved into a series of cones united at their bases, as in the chain of the Pentland Hills. A further stage in denudation brings us to isolated groups of cones completely separated from the rest of the rocks among which they once lay buried. Such groups may be carved out of a continuous band of rock extending into the regions beyond. The Paps of Jura, for instance, rise out of a long belt of quartzite which stretches through the islands of Islay, Jura and Scarba. In many cases, however, the groups point to the existence of some boss of rock of greater durability than those in the immediate neighbourhood, as in the Cuchullins and Red Hills of Skye and the group of granite cones of Ben Loyal, Sutherland. The most impressive form of solitary cone is that wherein after vast denudation a thick overlying formation has been reduced to a single outlier, such as Morven in Caithness, the two Bens Griam in Sutherland, and still more strikingly, the pyramids of red sandstone on the western margin of the shires of Sutherland and Ross and Cromarty. The horizontal stratification of some of these masses gives them a curiously architectural aspect, further increased by the effect of the numerous vertical joints by which the rock is cleft into buttresses and recesses along the fronts of the precipices and into pinnacles and finials along the summits. Solitary or grouped pyramids of red sandstone between 3000 and 4000 ft.
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above the sea are mere remnants of a continuous sheet of red sandstone that once spread far and wide over the western Highlands. Stratified rocks when they have not been much disturbed from their original approximate horizontality weather into escarpments. Such cliffs may run for many miles across a country, rising one above another into lofty terraced hills. In Scotland the rocks have been so dislocated and disturbed as to prevent the formation of continuous escarpments, and this form of rock-scenery is consequently almost entirely absent, except locally and for the most part on a comparatively small scale. The most extensive Scottish escarpments are found among the igneous rocks. Where lava has been piled up in successive nearly horizontal sheets, with occasional layers of tuff or other softer rock between them, it offers conditions peculiarly favourable for the formation of escarpments, as in the wide basalt plateaus of the Inner Hebrides. The Carboniferous lavas of the Campsie and Fintry Hills and of the south of Dumfriesshire and Roxburghshire likewise rise in lines of bold escarpment.
The lakes and water-basins may be classified in four groups, each with its own peculiar scenery and distinct mode of origin - (I) glen lakes, (2) rock-tarns, (3) moraine-tarns, (4) lakes of the plains.
Glen lakes
1. Glen lakes are those which occupy portions of glens. They are depressions in the valleys, not due to local heaping up of detritus, but true rock-basins, often of great depth. Much discussion has arisen as to their mode of origin, but it is probable they were caused by the erosive action of ice, since glaciers occupied the glens where they occur and wore down the rocks along the sides and bottom; but it is a point of difficulty in this theory whether ice could have eroded the deepest of the hollows. In any circumstances the lakes must be of recent geological date. Any such basins belonging to the time of the folding of the crystalline schists would have been filled up and effaced long ago. Indeed, so rapid is the infilling by the torrents which sweep down detritus from the surrounding heights that even the existing lakes are visibly diminishing. Glen lakes are almost wholly confined to the western half of the Highlands, where they form the largest sheets of fresh water. Hardly any lakes are to be seen east of a line drawn from Inverness to Perth. West of that line, however, they abound in both the longitudinal and the transverse valleys. The most remarkable line of them is that which fills up much of the Great Glen, Loch Ness being the largest. Other important longitudinal lakes are Lochs Tay, Awe, Ericht and Shiel. The most picturesque glen lakes, however, lie in transverse valleys, which being cut across the strike of the rocks present greater variety and, usually, abruptness of outline. Lochs Lomond, Katrine and Lubnaig in the southern Highlands, and Lochs Maree and More in the north, are conspicuous examples.
Rock-tarns
2. Rock-tarns are small lakes lying in rock-basins on the sides of mountains or the summits of ridges, and on rocky plateaus or plains. Unlike glen lakes, they have no necessary dependence upon lines of valley, but are scattered as it were broadcast, and are by far the most abundant of the Scottish lakes. Dispersed over all parts of the western Highlands, they are most numerous in the north-west, especially in the Outer Hebrides and in the west of the shires of Ross and Cromarty and Sutherland, where the surface of the Archean gneiss is so thickly sprinkled with them that many tracts consist nearly as much of water as of land. They almost invariably lie on strongly ice-worn platforms of rock, and are obviously hollows produced by the gouging action of the sheets of land-ice by which the general glaciation of the country was affected. In the Southern Uplands, owing to the greater softness and uniformity of texture of the rocks, rock-tarns are comparatively infrequent, except in Galloway, where the protrusion of granite and its associated metamorphism have reproduced Highland conditions of rock-structure. In the rocky hill-ranges of the Central Plain rock-tarns occasionally make their appearance.
Moraine-tarn
3. - small sheets of water ponded back by some of the last moraines shed by the retreating glaciers - are confined to the more mountainous tracts. Among the Southern Uplands the best-known and one of the most picturesque is the wild and lonely Loch Skene, lying in a recess of Whitecoomb at the head of Moffat Water. Others are sprinkled over the higher parts of the valleys in Galloway. None occurs in the Central Plain. In the Highlands they may be counted by hundreds, nestling in the bottoms of the corries. In the north-western counties, where the glaciers continued longest to descend to the sea-level, lakes retained by moraine-barriers may be found very little above the sea.
Lakes of the Plains
4. The Lakes of the Plains lie in hollows of the glacial detritus which is strewn so thickly over the lower grounds. As these hollows were caused by original irregular deposition rather than by erosion, they have no intimate relation to the present drainage-lines. The lakes vary in size from mere pools to sheets of water several square miles in area. As a rule they are shallow in proportion to their extent and surface. They were once more numerous than they are now, but some have disappeared through natural causes and others have been drained. The largest sheets of fresh water in the Lowlands are lakes of the plains as Loch Leven and the Lake of Menteith.
The eastern and western seaboards present a singular contrast. The eastern is indented by a series of broad arms of the sea - the firths of Forth and Tay, Moray and Dornoch firths - but is otherwise relatively unbroken. The land slopes gently to the sea or to the edge of cliffs that nave been cut back by the waves. The shores are for the most part low, with few islands in front of them, and culti vation comes down almost to the tide-line. The western - side, on the contrary, is from end to end intersected with long narrow sea lochs or fjords. The land shelves down rapidly into the sea and is fronted by chains and groups of islands. The explanation of this contrast must be sought in geological structure. The west side, as we have seen, has been more deeply eroded than the eastern. The glens are more numerous there and on the whole deeper and narrower. Many of them are prolonged under the sea; in other words, the narrow deep fjords are seaward continuations of the glens. The presence of the sea in these fjords is an accident. If they could be raised out of the sea they would become glens, with lakes filling their deeper portions. That this has been their history hardly admits of question. They are submerged landvalleys, and as they run down the whole western coast they show that this side has subsided to a considerable depth beneath its former level. The Scottish sea lochs must be considered in connexion with those of western Ireland and Norway. The whole of this northwestern coast-line of. Europe bears witness to recent submergence. The bed of the North Sea, which at no distant date in geological history was a land surface across which plants and animals migrated freely into Great Britain, sank beneath the sea-level, while the Atlantic advanced upon the western margin of the continent and filled the seaward ends of what had previously been valleys open to the sun. In this view the Outer and Inner Hebrides were formerly one with themselves and the mainland, and the western isles therefore are truly grouped with the Highland province of Scotland. Nearly the whole coast-line is rocky. On the east indeed, the shores of the estuaries are generally low, but the land between the mouths of these inlets is more or less precipitous. On the west the coast is mostly either a steep rocky declivity or a sea-wall, though strips of lower ground are found in the bays. The cliffs vary in character according to the nature of the rock. At Cape Wrath, precipices 300 ft. high have been cut out of the Archean gneiss. The varying texture of this rock, its irregular foliation and jointing, and its ramifying veins of pegmatite give it very unequal powers of resistance. Here it projects in irregular bastions and buttresses, there retires into deep recesses and tunnels, but shows everywhere a ruggedness of aspect eminently characteristic. In striking contrast to these precipices are those of the Cambrian red sandstone a few miles to the east. Vast vertical walls of rock shoot up to a height of 600 ft., cut by their perpendicular joints into quadrangular piers and projections, some of which stand out alone as cathedral-like islets in front of the main cliff. The sombre colouring is relieved by vegetation along the edges of the nearly flat beds which project like great cornices and serve as nesting-places for sea-fowl. On the west the most notable cliffs south of those of Cape Wrath and the Cambrian sandstones of Sutherland are to be found among the basaltic islands, particularly in Skye, where a magnificent range of precipices rising to moo ft. bounds the western coast-line. However, the highest cliffs are found among the Shetland and Orkney Islands. The sea-wall of Foula, in Shetland, and the western front of Hoy, in Orkney, rise like walls to heights of 1100 or 1200 ft. Caithness is one wide moor, terminating almost everywhere seaward in a range of precipices of Old Red Sandstone. Along the eastern coast most of the cliffs are formed of rocks belonging to this formation. Beginning at Stonehaven, an almost unbroken line of precipice varying up to 200 ft. in height runs to the mouth of the estuary of the Tay. On the east the Southern Uplands plunge abruptly into the sea near St Abb's Head in a noble range of precipices 300 to 500 ft. in height, and on the west terminate in a long broken line of sea-wall, which begins at the mouth of Loch Ryan, extends to the Mull of Galloway, and reappears again in the southern headlands of Wigtown and Kirkcudbright. Among the most picturesque features of Scottish sea-cliffs are the numerous stacks or columns of rock which during the demolition and cuttingback of the precipices have been isolated and left standing amidst the waves. These remnants attain their most colossal size and height on the cliffs of Old Red Sandstone. Thus the Old Man of Hoy in Orkney is a huge column of yellow sandstone between 400 and 500 ft. high, forming a conspicuous landmark in the north. The coast of Caithness abounds in outstanding pillars and obelisks of flagstone.
The low shores on the west coast are frequently occupied by sanddunes, as on the western margin of North and South Uist, and in many bays from the north of Sutherland to the coast of Ayrshire. They are more abundant on the east coast, however, especially on the shores of Aberdeenshire, between the mouths of the two Esks in Forfarshire, on both sides of the mouth of the Firth of Tay, and at various places on the Firth of Forth. Raised sea-beaches likewise play a part in the coast scenery. These alluvial terraces form a strip of low fertile land between the edge of the sea and the rising ground of the interior, and among the western fjords sometimes supply the only arable soil in their neighbourhood, their flat green surfaces presenting a strong contrast to the brown and barren moors that rise from them. Most of the seaport towns stand upon platforms of raised beach. Considerable deposits of mud, silt and sand are accumulating in many of the estuaries. In the Tay, Forth and Clyde, where important harbours are situated, great expense is involved in constantly dredging to remove the sediment continually brought down from the land and carried backwards and forwards by the tides.
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While no islands except mere solitary rocks like May Island, the Bass Rock and Inchkeith diversify the eastern seaboard, the western presents a vast number, varying from such extensive tracts as Skye to the smallest stack or skerry. Looked at in the broadest way, these numerous islands may be regarded as belonging to two groups or series, the Outer and the Inner Hebrides. In the Outer Hebrides most of the ground is low, rocky and plentifully dotted over with lakes; but it rises into mountainous heights in Harris, some of the summits attaining elevations of 2600 ft. The general trend of this long belt of islands is north-north-east. The Inner Hebrides form a much less definite group. They may be regarded as beginning with the Shiant Isles in the Minch and stretching to the southern headlands of Islay, and their irregularity has no doubt been chiefly brought about by the remarkable diversity of geological structure. Archean gneiss, Cambrian sandstone, Silurian quartzite, limestone and schist, Jurassic sandstone and limestone, Cretaceous sandstone, and Tertiary basalts, gabbros, and granitic rocks all enter into the composition of the islands.
Influence of Topography
The influence of the topography of the country on the history of its inhabitants has been all-important. How powerfully the configuration affects the climate is shown in the remarkable difference between the rainfall of the mountainous west and of the lowland east. This difference has necessarily modified the character and employment of the people, leading to the cultivation of the soil on the one side and the raising of sheep and cattle on the other. The fertile low grounds on the east have offered facilities for the invasions of Romans, Norsemen and English, while the mountain fastnesses of the interior and the west have served as secure retreats for the older Celtic population. While, therefore, Teutonic people have spread over the one area, the earlier race has to this day maintained its ground in the other. Not only external configuration but geological structure also has profoundly influenced the progress of the inhabitants. In the Highlands no mineral wealth has been discovered to stimulate the industry of the natives or to attract labour and capital. These tracts remain still, as of old, sparsely inhabited and given over to the breeding of stock and the pursuit of game. In the Lowlands, on the other hand, rich stores of coal, iron, lime and other minerals have been found. The coal-fields have gradually drawn to them an ever-increasing share of the population. Villages and towns have suddenly developed and rapidly increased in size. Manufactures and shipbuilding have grown and commerce has advanced with accelerated pace. Other influences have of course contributed largely to the development of the country, but among them all the chief place must be assigned to that fortunate geological structure which, amid the revolutions of the past, has preserved in the centre of Scotland those fields of coal and ironstone which are the foundations of the national industry.
Geology
Archean Rocks
The oldest rocks of Scotland and of the British Isles are known, from their antiquity, as Archean, and consist chiefly -of gneiss (called Fundamental, as lying at the foundation of the geological structure of the country, and Lewisian and Hebridean, because it is well developed in the island of Harris and the Outer Hebrides), which varies from a coarsely crystalline granitoid mass -to fine schist. The coarse varieties are most abundant, intermingled with bands of hornblende-rock, hornblende-schist, pegmatite, eucrite, mica-schist, sericite-schist and other schistose accompaniments. In a few places limestone has been observed. No trace of any -organism has ever been detected in any of these rocks. Over wide areas, particularly on the mainland, the bands of gneiss have a general north-west trend and undulate in frequent plications with variable inclination to north-east and south-west. The largest tract -of Archean rock is that which forms almost the whole of the Outer Hebrides, from Barra Head to the Butt of Lewis. Other areas more or less widely separated from each other run down the western parts of the shires of Sutherland and Ross and Cromarty, and are probably -continued at least as far as the island of Rum.Eastern or Younger Schists
The central, southern and eastern Highlands are occupied by metamorphosed sedimentary and igneous rocks, to which has been provisionally assigned the name of Dalradian, from the old Celtic kingdom of Dalriada. Their true stratigraphical position has not yet been ascertained, and it may appear that more than one group of rocks is included in the series. Eastward of the Archean gneiss in the west of Sutherland the effect of enormous underground pressure has been to upraise masses of the ancient gneiss and Torridonian sandstone and thrust them westward over the younger rocks. It is not possible to say what was the original character of many of the disrupted materials, for they have been rearranged and re-crystallized into granulitic, flaggy gneisses and schists (Moine schists). They extend from the north-east of Sutherland as far south as the Sound of Mull. To the east of the dislocation of the Great Glen these puzzling rocks may also be met with, though in that tract most of the surface comprises sedimentary and igneous rocks, the metamorphism of which has varied much. Immense -sheets of dolerite, gabbro, or allied basic rocks indicate eruptive materials intruded as sills or poured out as lavas contemporaneously with the sedimentary formations among which they lie. On the ,other hand, there occur bands of conglomerate, pebbly grit, quartzite, graphitic shale and limestone in a certain ordered sequence and over a wide area. Traces of annelids have been detected in some of the quartzites, and some of the less changed parts of the limestones may be searched for fossils. This great series of metamorphic rocks, the geological age of which is still unsettled, has had a powerful effect on the scenery, especially along the Highland line. Where a thick group of coarse hard grits intercalated in the sedimentary rocks crops out it rises into a chain of lofty rugged hills, of which Ben Ledi and Ben Vorlich are examples. The slate hills, weathering more readily, assume gentle slopes and rounded ridges, as in the high land from Holy Loch to the Kyles of Bute. The quartzites rise in conical hills, such as those of Jura and Islay. And to the soil created by the decay of the limestones is due a greener verdure than that of the surrounding moors.
Torridonian Sandstone
Above the Archean gneiss lies a series of red and chocolate-coloured sandstone (Torridon sandstone), which form a number of detached areas from Cape Wrath down the seaboard of the shires of Sutherland and Ross and Cromarty, across Skye, and as far as the island of Rum. They rise into prominent pyramidal mountains, which, as the stratification is usually almost horizontal, present in their terraced sides a singular contrast to the neighbouring heights, composed of highly plicated crystalline schists. In the Torridon district they can be seen towering bed above bed to a height of about 4000 ft., but they must be at least Io,000 ft. thick. They are not met with anywhere else in Scotland. Traces of annelids and probably other organisms have been found in the bands of shale occurring in the south-west of the shire of Ross and Cromarty, in the isle of Raasay, and at Cailleach Head, and are the oldest relics of animal life yet found in Great Britain.
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Cambrian
In the north-western Highlands masses of white quartzite, resting unconformably in Torridonian sandstone, run from Loch Eriboll to Skye, forming in places great conical hills and some L J Recent & Pleistocene F l Cretaceous Jurassic Trias Granite & Acid Intrusive Rocks' Permian Coal Measures, Carboniferous Millstone Grit Series Lower Carboniferous Old Red Sandstone & Devonian Silurian Ordovician Cambrian Scale, z:4,600.000 English Miles o xxxx xzxx xxxx Metamorphic Group Volcanic Rocks ® Basic Intrusive Rocks 'I +++ +++ ob.o times capping isolated mountains of red Torridon sandstone. They constitute the lowest group of the most interesting series of strata in the Highlands, and yield a large number of fossils. In descending order they embrace the following subdivisions, whose thickness in the district of Durness is estimated at about 2000 ft.: (e) limestones, dolomites and cherts, with numerous organic remains; (d) grit and quartzite, with Saltarella and Olenellus (Serpulite Grit); (c) calcareous shales and dolomites, with many annelid casts and sometimes Olenellus (Fucoid Beds); (b) Upper Quartzite, often crowded with annelid pipes (Pipe Rock Quartzite); (a) Lower Quartzite - their original upper limit can nowhere be seen, for they have been overridden by the Eastern Schists in those gigantic underground disturbances already referred to, by which these rocks, the Archean gneiss and Torridonian sandstone, were crumpled, inverted, dislocated and thrust over each other. The quartzites themselves have also been subjected to extraordinary horizontal displacement, amounting in places to not less than Io m. The rocks overlying them to the east of the line of disturbance in the shires of Sutherland and Ross and Cromarty are fine flaggy schists. The Cambrian system - including the Upper (Durness-Eriboll Limestone) and the Lower (Serpulite grit, Fucoid Beds, Quartzite) - forms a narrow band which can be traced for too m. from the north coast of Sutherland to Skye. Rocks of Cambrian age have not been identified elsewhere in Scotland, though it may ultimately be shown that the quartzites and limestones of the Central Highlands are equivalents of those of the north-west coast.
Ordovician and Silurian
In the Southern Uplands a great development of Ordoviciar.. and Silurian rocks is found. In that belt they consist mostly of greywacke, grit, shale and other sedimentary rocks, but in the southwest of Ayrshire they include some thick lenticular bands of limestone. They have been thrown into many folds, the long axes of which run in a general north-easterly direction. It is this structure which has determined the trend of the southern Uplands. The plications of the Highlands and the chief dislocations of the country have followed the same general direction, and hence the parallelism and north-easterly trend of the main topographical features. Abundant fossils (grapholites principally) in certain parts of these rocks have shown that representatives of both the Ordovician and Upper divisions are present. By far the larger part of the Uplands belongs to the former. The Upper Silurian shales and sandstones appear only along the northern and southern margins. The coast on both sides of the country shows good sections of the rocks, the Berwickshire cliffs being particularly fine. Those of Ayrshire and Galloway are lower and more accessible, and permit of study of the plication of the strata. Among the best localities for fossils are Moffat Water, in Dumfriesshire, for graptolites, and the Pentlands, in Midlothian. Balmae, on the southern shore of Kirkcudbrightshire, the coast south of Girvan and the limestone quarries of the Stinchar and Girvan valleys, in Ayrshire, for shells, trilobites, corals, &c.
Old Red Sandstone
Scotland is the typical European region for the deposits classed as Old Red Sandstone. These rocks are grouped in two divisions, Lower and Upper, both of which appear to have been deposited in lakes. The Lower, with its abundant intercalated lavas and tuffs, extends continuously as a broad belt along the northern margin of the Central Plain, reappears in detached tracts along the southern border, is found again on the south side of the Uplands in Berwickshire and the Cheviot Hills, occupies a tract of Lorne (Oban and the vicinity) in Argyllshire, and on the north side of the Highlands underlies most of the low ground on both sides of the Moray Firth, stretches across Caithness and through nearly the whole of the Orkney Islands, and is prolonged into Shetland. The Upper Old Red Sandstone covers a more restricted space in most of the areas just mentioned, its chief development being on the flanks of the north-eastern part of the Southern Uplands, where it spreads out over the Lammermuir Hills and the valleys of Berwickshire and Roxburghshire. The Lower Old Red Sandstone is rich in remains of plants and fishes, notably in the flagstones of Caithness, Orkney and Forfarshire. The volcanic rocks of this division form ranges of hills in the Lowlands, such as the Pentlands, Ochils and Sidlaws. They have in some places a thickness of 7000 ft. The lavas are usually porphyrites, which occur in sheets, with intercalated bands of volcanic tuff that are sometimes strongly felsitic. One of the vents by which such materials were ejected occurs in the Braid Hills on the south side of Edinburgh. Fossils are less common in the Upper Old Red Sandstone, though they are found - particularly fishes - in large numbers in certain spots, as at Dura Den, near Cupar-Fife. Traces of contemporaneous volcanic action exist in the Orcadian island of Hoy.
Carboniferous
The areas occupied by Carboniferous rocks are almost entirely restricted to the Central Plain or Lowlands, but they are also found skirting the Southern Uplands from the mouth of the Tweed to that of the Nith. In the basins of the Forth and Clyde the following subdivisions are well marked: (5) Upper Red Sandstone series (red and grey sandstones, fireclays, shales, marls); (4) Coal Measures (white and grey sandstones, dark shales, fireclays, coal seams, ironstones); (3) Millstone Grit (massive sandstones and grits, with fireclays, thin limestones and coal); (2) Carboniferous Limestone series - (c) sandstones and shales, with three or more seams of limestone; (b) sandstones, shales, coals and ironstones, but with no limestone bands; (a) sandstones, shales, fireclays, coals and iron XXIV. 14 stones, with thin limestones towards the top and the Hurlet (Renf rewshire) limestone at the bottom; (I) Calciferous Sandstone series - (b) Upper or Cement Stone group, consisting of white and grey sandstones (of which the city of Edinburgh was built), black shales, thin limestones (Burdiehouse, near Edinburgh), and occasional coal seams; (a) Lower Red Sandstone group, with reddish and greenish marls and shales, passing down with the Upper Old Red Sandstone. The coal-fields contain two main groups of seams, the lower in the middle section of the Carboniferous Limestone, and the upper in the Coal Measures. The thin seams of the Calciferous Sandstone are not workable, but the bituminous shales in the Firth of Forth basin are largely worked for the manufacture of mineral oil. The plant-life of the Carboniferous was exceedingly luxuriant and varied, and the system is rich also in fossils of fishes, crustaceans, mollusca, insects and other forms of animal life. There was great volcanic activity during the deposition of the Calciferous Sandstone, Carboniferous Limestone and Millstone Grit series. The two leading types of volcanic areas are the plateaus, in which sheets of porphyrites, basalts and even trachytes were emitted, sometimes with wide discharge of volcanic ashes, and the puys, or isolated vents, or scattered groups of vents, which discharged comparatively a small amount of lava and ashes. The Campsie, Kilpatrick and Dumbarton hills, the high ground from Greenock to Ardrossan, and the Carleton Hills in East Lothian are examples of the plateaus, while Arthur's Seat in Edinburgh and the Binn of Burntisland illustrate the puys. Most of the hills and crags in the Carboniferous area are volcanic, and many of them - such as the castle rocks of Edinburgh and Stirling, Binny Craig in Linlithgowshire, North Berwick Law and the Bass Rock - mark the sites of actual events of eruption.
Permian
Rocks assignable to the Permian system occupy only a few small areas in Scotland. They fill up the valley of the Nith for a few miles north of Dumfries, and, reappearing again in the same valley a little farther north, run up the narrow valley of the Carron to the Lowther Hills. Other detached tracts cover a considerable space in Annandale, one of them ascending the deep defile, known as the Devil's Beef Tub, at the head of that valley. Another isolated patch occurs among the Lead Hills; and lastly, a considerable space in the heart of the Ayrshire coal-field is occupied by Permian rocks. Throughout these separate basins the prevailing rock is a red sandstone, varied in the narrow valleys with intercalated masses of breccia. There can be no doubt that the valleys in which these patches of red rocks lie already existed in Permian time. They seem then to have been occupied by small lakes or inlets, not unlike fjords. Numerous amphibian tracks have been found in the red sandstone of Annandale and also near Dumfries, but no other traces of the life of the time. One of the most interesting features of the Scottish development of the Permian system is the occurrence of intercalated bands of contemporaneously erupted volcanic rocks in the Carron, Nithsdale and Ayrshire. The actual vents which were the sites of the small volcanoes still remain distinct, and the erupted lavas form high ground in the middle of Ayrshire.
Triassic
The Triassic system is only feebly represented. The largest tract occurs in the south of Dumfriesshire between Annan and the head of the Solway Firth. To this division are assigned the yellow sandstones of Elgin, which have yielded crocodilian and other reptilian remains, the discovery of which led to the rocks being separated from the Upper Old Red Sandstone, to which they had previously been thought to belong. There occur also below the Lias on some parts of the west coast unfossiliferous red sandstones, conglomerates and breccias, presenting lithological resemblance to the Rhaetic group of England. Such strata are well seen in the isle of Raasay and near Heast in Skye. Red sandstones and conglomerates, probably of the same age, attain a thickness of several hundred feet at Gruinard Bay on the west coast of the county of Ross and Cromarty. On the east side of Scotland, where so many fragments of the Secondary rocks occur as boulders in the glacial deposits, a large mass of strata was formerly exposed at Linksfield to the north of Elgin, containing fossils which appear to show it to belong to the Rhaetic beds at the top of the Trias. But it was not in place, and was probably a mass transported by ice. Rhaetic strata no doubt exist in situ at no great distance under the North Sea.
Jurassic
The Jurassic system - comprising, in descending order, the subdivisions of Upper Oolites (Portlandian Kimmeridge Clay), Middle Oolites (coal limestones; Oxford clay), Lower Oolites (Great Oolite series; Inferior Oolite series), Lias (Upper, Middle, Lower) - is well represented on both sides of the Highlands. Along the east coast of Sutherland good sections are exposed showing the succession of strata. Among these the Lower and Middle Lias can be identified by their fossils. The Lower Oolite is distinguished by the occurrence in it of some coal-seams, one of which, 31 ft. in thickness, has been worked at Brora. The Middle Oolite consists mostly of sandstones with bands of shale and limestones, and includes fossils which indicate the English horizons from the Kellaways Rock up to the Coral Rag. The lower part of the Kimmeridge Clay is probably represented by sandstones and conglomerates, forming the highest beds of the series in Sutherland. On the west side of the Highlands Jurassic rocks are found in many detached areas from the Shiant Isles to the southern shores of Mull. Over much of this region they owe their preservation largely to the mass of lavas poured over them in Tertiary time. They have been uncovered, indeed, only at a comparatively recent geological date. They comprise a consecutive series of deposits from the bottom of the Lias up to the Oxford Clay. The Lower, Middle and Upper Lias consist chiefly of shales and shelly limestones, with some sandstones, well seen along the shores of Broadford Bay in Skye and in some of the adjacent islands. The Lower Oolites are made up of sandstones and shales with some limestones, and are overlaid by several hundred feet of an estuarine series of deposits consisting chiefly of thick white sandstones, below and above which lie shales and shelly limestones. These rocks form a prominent feature underneath the basalt terraces of the east side of Skye, Raasay and Eigg. They form the highest members of the Jurassic series, representing probably some part of the Oxford Clay. The next Secondary rocks (Cretaceous) succeed them unconformably.
Cretaceous
Rocks belonging to the Cretaceous system at one time covered considerable areas on both sides of the Highlands, but they have been entirely stripped off the eastern side, while on the western they have been reduced to a few fragmentary patches, which have survived because of the overlying sheets of basalt that have protected them. Some greenish sandstones containing recognizable and characteristic fossils are the equivalents of the Upper Greensand of the south of England. These rocks are found on the south and west coasts of Mull and on the west coast of Argyllshire. They are covered by white sandstones and these by white chalk and manly beds, which represent the Upper Chalk of England. Their existence under the basalt outlier of Ben Iadain in Morven, at a height of 1600 ft. above the sea, shows notably how extensively they have been denuded, but also over how large a portion of the Western Highland seaboard they may have spread. They are a prolongation of the Cretaceous deposits of Antrim (Ireland). Enormous numbers of flints and also less abundant fragments of chalk are found in glacial deposits bordering the Moray Firth. These transported relics show that the Chalk must once have been in place at no great distance, if indeed it did not actually occupy part of Aberdeenshire and the neighbouring counties.
Older Tertiary
Above the highest Secondary rocks on the west coast come terraced plateaus of basalt, which spread out over wide areas in Skye, Eigg, 1VIull and Morven, and form most of the smaller islets of the chain of the Inner Hebrides. These plateaus are composed of nearly horizontal sheets of basalt - columnar, amorphous or amygdaloidal - which, in Ben More, in Mull, attain a thickness of more than 3000 ft. They are prolonged southwards into Antrim, where similar basalts overlying Secondary strata cover a large territory. Occasional beds of tuff are intercalated among these lavas, and likewise seams of fine clay or shale which have preserved the remains of numerous land-plants. The presence of these fossils indicates that the eruptions were subaerial, and a comparison of them with those elsewhere found among Older Tertiary strata shows that they probably belong to the Oligocene stage of the Tertiary series of formations, and therefore that the basalt eruptions took place in early Tertiary time. The volcanic episode to which these plateaus owe their origin was one of the most important in the geological history of Great Britain. It appears to have resembled in its main features those remarkable outpourings of basalt which have deluged so many thousand square miles of the western area of the United States. The eruptions were connected with innumerable fissures up which the basalt rose and from numerous points on which it flowed out at the surface. These fissures with the basalt that solidified in them now form the vast assemblage of dykes which cross Scotland, the north of England and the north of Ireland. That the volcanic period was a prolonged one is shown by the great denudation of the plateaus before the last eruptions took place. In the Isle of Eigg, for example, the basalts had already been deeply eroded by river-action and into the river-course a current of glassy lava (pitch-stone) flowed. Denudation has continued active ever since, and now, owing to greater hardness and consequent power of resistance, the glassy lava stands up as the prominent and picturesque ridge of the Scuir, while the basalts which formerly rose high above it have been worn down into terraced declivities that slope away from it to the sea. A remarkable feature in the volcanic phenomena was the disruption of the basaltic plateaus by large bosses of gabbro and of various granitoid rocks. These intrusive masses now tower into conspicuous groups of hills - the Cuillins in Skye, the mountains of Rum and Mull, and the rugged heights of Ardnamurchan.
Post-Tertiary
Under the Post-Tertiary division come the records of the Ice Age, when Scotland was buried under sheets of ice which ground down, striated and polished the harder rocks over the whole country, and left behind them the widespread accumulation of clay, gravel and sand known as Glacial Deposits. The Till or Boulder Clay, the most universal kind of Drift - which covers much of the Lowlands to a depth sometimes of roo ft., and along the flanks of hills reaches a height of 2000 ft. or more - was pushed along by ice radiating from different centres, evidence of which is to be seen in the direction of the striae on the rocky surface of the country as well as in the dispersion of boulders and stones from recognizable districts. Thus remains of Highland schists have been borne across the Central Plain and deposited on the northern margin of the Southern Uplands. Above the Boulder Clay are found sands and gravels, along with perched boulders which, by their source and position, indicate the direction and thickness of the ice that carried them. Moraines of the last of the glaciers are numerous throughout the Highlands.
Recent
The youngest formations are the raised beaches - consisting sometimes of ledges cut in the rock, as on Lismore and other parts of Loch Linnhe, and sometimes of heaped-up beds of sand and gravel - river terraces, lake deposits, peat-mosses, tracts of blown sand - notably seen in the dunes of Culbin, Rattray Head, Aberdeen, Montrose and Tents Muir on the east coast, and at Stevenston, Troon, Ayr, Glenluce and along North and South Uist on the west. These are related to the present configuration of the land and contain remains of plants and animals still living on its surface. (A. GE.; A. M.)Climate
In considering the climate of Scotland the first place must be assigned to the temperature of various districts during the months of the year, since this, and not the mean temperature of the whole year, gives the chief characteristics of climate. Thus, while the annual temperatures of the west and east coasts are nearly equal, the summer and winter temperatures are very different. At Portree (on the east coast of Skye) the mean temperatures of January and July are 39° and 56.8° F., whereas at Perth they are 37.5° and 59.0°. The prominent feature of the isotherms of the winter months is their north and south direction, thus pointing not to the sun but to the warm waters of the Atlantic as the more powerful influence in determining the climate at this season through the agency of the prevailing westerly winds. In exceptionally cold seasons the ocean protects all places in its more immediate neighbourhood against the severe frosts which occur in inland situations. While this influence of the ocean is felt at all seasons, it is most strikingly seen in winter and is more decided in proportion as the locality is surrounded by the warm waters of the Atlantic. The influence of the North Sea is similarly apparent, but in a less degree. Along the whole ' of the eastern coast, from the Pentland Firth southwards, temperature is higher than what is found a little inland. In summer, everywhere, latitude for latitude, temperature is lower in the west than in the east and inland situations, but in winter the inland climates are the colder. The course of the isothermal lines in summer is very instructive. Thus the line of 59° passes from the Solway directly northwards to the north of Perthshire and thence curves round eastward to near Stonehaven. From Teviotdale to the Grampians temperature falls only one degree; but for the same distance farther northwards it falls three degrees. The isothermal of 56° marks off the districts where the finer cereals can be successfully raised. This distribution of the temperature shows that the influence of the Atlantic in moderating the heat of summer is very great and is felt a long way into the interior of the country. On the other hand, the high lands of western districts by robbing the westerly winds of their moisture, and thus clearing the skies of eastern districts, exercise an equally striking effect in the opposite direction - in raising the temperature.There is nearly twice as much wind from the south-west as from the north-east, but the proportions vary greatly in different months. The south-west prevails from July to October, and again from December to February; accordingly in these months the rainfall is heaviest. These are the summer and winter portions of the year, and an important result of the prevalence of these winds, with their accompanying rains, which are coincident with the annual extremes of temperature, is to imprint a more strictly insular character on the climate, by moderating the heat of summer and the cold of winter. The north-east winds acquire their greatest frequency from March to June and in November, which are accordingly the driest portions of the year.
The mountainous regions are mostly massed in the west and lie generally north and south, or approximately facing the rain-bringing winds from the Atlantic. Thus the climates of the west are essentially wet. On the other hand, the climates of the east are dry, because the surface is lower and more level; and the breezes borne thither from the west, being robbed of most of their superabundant moisture in crossing the western hills, are drier and precipitate a greatly diminished rainfall. It thus happens that the driest climates in the east are those which have to south-westwards the broadest extent of mountainous ground, and that the wettest eastern climates are those which are least protected by high lands on the west. The breakdown of the watershed between the Firths of Clyde and Forth exposes southern Perthshire, the counties of Clackmannan and Kinross, and nearly the whole of Fife to the clouds and rains of the west, and their climates are consequently wetter than those of any others of the eastern slopes of the country. The driest climates of the east are in Tweeddale about Kelso and Jedburgh, the low grounds of East Lothian, and those on the Moray Firth from Elgin round to Dornoch. In these districts the annual rainfall averages 26 in., whereas over extensive breadths in the west it exceeds too in., in Glencroe being nearly 130 in., and on the top of Ben Nevis it may reach 150 in.
II. Economic Conditions, &c.
Population
At the end of the 15th century it is conjectured that the population of Scotland did not exceed 500,000 - Edinburgh having about 20,000 inhabitants, Perth about 9000, and Aberdeen, Dundee and St Andrews about 4000 each. By the Union with England (1707) the population is supposed to >>418<map>419<< have grown to 1,000,000. In 1755, according to the returns furnished by the clergy to the Rev. Dr Alexander Webster (1707-1784), minister of the Tron Kirk, Edinburgh -who had been commissioned by Lord President Dundas to prepare a census for government,- it was 1,265,380. At the first government census (1801) it had reached 1,608,420. The increase at succeeding decades has been continuous though fluctuating in amount, and in 1901 the population amounted to 4,472,103 (females, 2,298,348). In 1902 the Registrar-General for Scotland calculated that if the rate of increase (11.09%) manifest during 1891-1901 were uniformly maintained, the population would double itself in the course of about 66 years.Table I.-Area and Population of Civil Counties in 1891 and 1901.
| Civil Counties. | Area in Acres. | Population. | Pop. per sq. m. 1901. | |
|---|---|---|---|---|
| 1891. | 1901. | |||
| I. Northern. | ||||
| 1. Shetland | 352,889 | 28,711 | 28,166 | 51 |
| 2. Orkney | 240,476 | 30,453 | 28,699 | 76 |
| 3. Caithness | 438,878 | 37,177 | 33,870 | 49 |
| 4. Sutherland | 1,297,849 | 21,896 | 21,440 | II |
| 2,330,092 | 118,237 | 112,175 | 31 | |
| II. North-Western. | ||||
| 1,976,707 | 78,727 | 76,450 | 25 | |
| 6. Inverness | 2,695,037 | 90,121 | 90,104 | 21 |
| 4,671,744 | 168,848 | 166,554 | 23 | |
| III. North-Eastern. | ||||
| 7. Nairn | 103,429 | 9,155 | 9,291 | 57 |
| 305,119 | 43,471 | 44,800 | 94 | |
| 9. Banff | 403,364 | 61,684 | 61,488 | 98 |
| 10. Aberdeen | 1,261,887 | 284,036 | 304,439 | 154 |
| 11. Kincardine | 243,974 | 35,492 | 40,923 | 107 |
| 2,317,773 | 433,838 | 460,941 | 127 | |
| IV. East Midland. | ||||
| 12. Forfar | 559,171 | 277,735 | 284,082 | 325 |
| 13. Perth | 1,595,774 | 122,185 | 123,283 | 49 |
| 14. Fife | 322,844 | 190,365 | 218,840 | 434 |
| 15. Kinross | 52,410 | 6,673 | 6,981 | 85 |
| 16. Clackmannan | 34,927 | 33,140 | 32,029 | 587 |
| 2,565,126 | 630,098 | 665,215 | 166 | |
| V. West Midland. | ||||
| 17. Stirling | 288,842 | 118,021 | 142,291 | 315 |
| 18. Dumbarton | 157,433 | 98,014 | 113,865 | 463 |
| 19. Argyll | 1,990,471 | 74,085 | 73,642 | 24 |
| 20. Bute | 139,658 | 18,404 | 18,787 | 86 |
| 2,576,404 | 308,524 | 348,585 | 87 | |
| VI. South-Western. | ||||
| 21. Renfrew | 153,332 | 230,812 | 268,980 | 1123 |
| 22. Ayr | 724,523 | 226,386 | 254,468 | 225 |
| 23. Lanark | 562,821 | 1,105,899 | 1,339,327 | 1523 |
| 1,440,676 | 1,563,097 | 1,862,775 | 827 | |
| VII. South-Eastern. | ||||
| 24. Linlithgow | 76,861 | 52,808 | 65,708 | 547 |
| 25. Edinburgh | 234,339 | 434,276 | 488,796 | 1335 |
| 26. Haddington | 171,011 | 37,377 | 38,665 | 145 |
| 27. Berwick | 292,577 | 32,290 | 30,824 | 67 |
| 28. Peebles | 222,599 | 14,750 | 15,066 | 43 |
| 29. Selkirk | 170,762 | 27,712 | 23,356 | 88 |
| 1,168,149 | 599,213 | 662,415 | 363 | |
| VIII. Southern. | ||||
| 30. Roxburgh | 426,060 | 53,500 | 48,804 | 73 |
| 31. Dumfries | 686,302 | 74,245 | 72,571 | 68 |
| 32. Kirkcudbright | 575,565 | 39,985 | 39,383 | 44 |
| 33. Wigtown | 311,609 | 36,062 | 32,685 | 67 |
| Grand Total | 1,999,536 | 203,792 | 193,443 | 62 |
| SCOTLAND | 19,069,500 | 4,025,647 | 4,472,103 | 150 |
In 1901 there were 150 persons to each square mile, and 4.3 acres (excluding inland waters, tidal rivers and foreshore) to each person. The distribution of population is illustrated in the preceding table, which gives the names and areas of the counties and other particulars.
In the northern, north-western and southern divisions the population declined during the decade, the fifteen counties thus affected being, in the order of decrease, beginning with the shire in which it was smallest, Inverness, Banff, Argyll, Kirkcudbright, Shetland, Sutherland, Dumfries, Ross and Cromarty, Clackmannan, Berwick, Orkney, Roxburgh, Caithness, Wigtown and Selkirk. It will thus be seen that the far north and far south alike decreased in population, the decline being largely due to physical conditions, though it need not be supposed that the limit of population was reached in either area. The most sparsely inhabited county was Sutherland, the most densely Lanark. The counties in which there was the largest increase in the decennial period-with Linlithgow first, followed by Lanark, Stirling, Renfrew, Dumbarton and thirteen others-principally belonged to the Central Plain, or Lowlands, in which, broadly stated, industries and manufactures, trade, commerce and agriculture and educational facilities have attained their highest development. In every county the population increased between 1801 and 1841, the increase being more than Io% in each county with the exception of Argyll, Perth and Sutherland. After 1841, however, the population in several Highland shires-in which the clearance of crofters to make way for deer was one of the most strongly-felt grievances among the Celtic part of the people-in the islands, and in some of the southern counties, diminished. The next table affords a comparison of the numbers of the population as grouped in towns, villages and rural districts, and in the mainland and islands.
Table II.-Population in Towns, Villages and Rural Districts, Mainland and Islands, 1891 and 1901.
| Groups. | Population. | Percentage of Pop. in each to total Pop. | ||
|---|---|---|---|---|
| 1891. | 1901. | 1891. | 1901. | |
| Towns1 | 2,631,298 | 3,120,241 | 65.37 | 69'77 |
| Villages1 | 465,836 | 4 66, 0 53 | 11.57 | 10'42 |
| Rural districts . | 928,513 | 885,809 | 23.06 | 19'81 |
| Total | 4,025,647 | 4,472,103 | Ioo oo | 100.00 |
| Mainland. . | 3, 86 5,74 8 | 4,3 16 ,55 1 | 96'03 | 96.52 |
| Islands.. . | 159,899 | 1 55,55 2 | 3.97 | 3.48 |
| Total | 4,025,647 | 4,47 2, 10 3 | Ioo oo | 100.00 |
1. Villages have populations of from 300 to 2000; towns from 2000 upwards.
Table III. gives the population of towns with more than 30,000 inhabitants.
Table III.-Population in chief Towns in 1881, 1891 and 1901.
| Town. | 1881. | 1891. | 1901. |
| Glasgow. .. | 55 1 ,4 1 5 | 5 6 5, 8 39 (of enlarged | 760,468 |
| area, 658,198) | |||
| Edinburgh. .. . | 228 ,357 | 261,225 (of enlarged | 316,523 |
| area) | |||
| Dundee. .. . | 140,239 | 153,330 | 160,878 |
| Aberdeen. .. . | 105,189 | 121,623 | 153,503 |
| Paisley. .. . | 55,638 | 166,425 | 79,354 |
| Leith | 59,485 | 67,700 | 76,668 |
| Govan | 50,492 | 63,625 | 76,350 |
| Greenock. .. . | 66,704 | 63,423 | 67,672 |
| Partick. ... . | 27,410 | 36,538 | 54,281 |
| Coatbridge. .. . | 24,812 | 30,034 | 36,991 |
| Kilmarnock.. . | 23,901 | 28,447 | 34,165 |
| Kirkcaldy. .. . | 23,632 | 27,151 | 34,063 |
| Perth | 28,980 | 29,899 | 32,886 |
| Hamilton. .. . | 18,517 | 24,859 | 32,775 |
| Motherwell | 12,904 | 18,726 | 30,418 |
The burghs in which the largest proportion of Scottish-born persons lived in 1901 were Kirkcaldy (with 95'997 in every loo of its inhabitants), Aberdeen (with 94'997), Perth (with 94.44 2) and Kilmarnock (with 94.046). The largest proportion of English-born were found in Edinburgh (with 5.43 8%) and Leith (with 4.481). Irish-born were most in evidence in Coatbridge (with 15.158 in every ioo), Partick (with 12.05) and Govan (with 11.51). Welsh nationality was most marked in Motherwell (with 0.250%). Those of British-Colonial birth were most numerous in Edinburgh (with 0.933%), and foreigners in Glasgow (with 0.890), Leith (with 0.741) and Hamilton (with 0.720). In addition to the 17,654 resident foreigners there were 4973 foreigners casually in Scotland at the taking of the census in 1901 (1839 men and women on board foreign and British vessels), raising the total of foreigners actually enumerated >>419-420<< to 22,627 (males 14,448), of whom 10,373 were of Russian nationality, 4051 of Italian, and 3232 of German.
Table IV. shows the nationalities of the people in 1891 and 1901.
Table IV.-Illustrating Nationalities in 1891 and 1901.
| Where Born. | Scotland, 1891. | Scotland, 1901. | ||
|---|---|---|---|---|
| Number. | Percentage of Pop. | Number. | Percentage of Pop. | |
| Scotland.. . | 3,698,700 | 91.63 ' | 4, 08 5,755 | 91'361 |
| Ireland.. . | 184,807 | 4'84 | 205,064 | 4'585 |
| England.. . | 108,736 | 2.70 | 131,350 | 2.937 |
| Wales. . | 2,309 | 0.06 | 2,673 | 0.060 |
| Isle of Man and the Channel | 927 | 0.02 | 1,058 | 0.024 |
| Islands | ||||
| British Colonies . British born | 13,607 | 0.39 | 15,907 | 0.355 |
| abroad, by naturalization and at sea | 8,051 | 0.20 | 12,642 | 0.283 |
| Foreigners . | 8,510 | 0.21 | 17,654 | 0'395 |
| Total | 4,025,647 | 100 | 4,472,103 | Ioo |
Table V. gives the number of persons, exclusive of children under three years of age, who spoke Gaelic only, and Gaelic and English, with their percentages to the population in 1901. The counties in which the highest percentages obtained of persons speaking Gaelic only were Ross and Cromarty with 15.92% (12,171 persons) and Inverness with 13.01% (11,722 persons). But in no fewer than eighteen counties the proportion of Gaelic-speaking persons was under I %.
Table V.-Showing Number of Persons aged three years and upwards speaking Gaelic only and Gaelic and English in 1901.
| Area. | Population. p | Gaelic only. y | Percentage. g | Gaelic and English. | Percentage. g |
| Scotland. .. . | 4,472,103 | 28,106 | 0.63 | 202.700 | 4'53 |
| Northern portion . | 1 ,753,47 0 | 27,854 | 1.59 | 160,915 | 9'18 |
| Southern portion . | 2,718,633 | 252 | 0.01 | 41,785 | 1'54 |
| Northern division . | 112,175 | 489 | 0.43 | 17,084 | 15'23 |
| North-western „ | 166,554 | 23,893 | 14'34 | 82,573 | 49'58 |
| North-eastern „ | 460,941 | 20 | 0.01 | 5,125 | 1.11 |
| East-midland „ | 665,215 | 95 | 0.01 | 13,818 | 2.06 |
| West-midland „ | 348,585 | 3,357 | 0'96 | 42,315 | 12.14 |
| South-western „ | 1,862,775 | 162 | 0.01 | 34,289 | 1'84 |
| South-eastern „ | 662,415 | 89 | 0.01 | 7,002 | 1.06 |
| Southern„ | 193,443 | I | 0.00 | 494 | 0.26 |
Vital Statistics
In Table VI. is shown the number of births, deaths, marriages and illegitimate births for the decades ending 1870, 1880, 1890 and 1900.Table VII. gives the percentages to the population of the births, deaths and marriages in the four decades specified, along with the ratio of illegitimacy to the total number of births in the same periods.