The British Isles form a group lying off the north-west coast of Europe with a total area of 121,600 square miles. The largest islands are Great Britain proper (comprising the mainlands of England, Wales and Scotland) and Ireland (comprising Northern Ireland and the Irish Republic). Off the southern coast ofEnglandis the Isle of Wight and off the extreme south-west are the Isles of Scilly; off North Wales is Anglesey.Western Scotlandis fringed by numerous islands and to the far north are the important groups of the Orkneys and Shetlands. All these form administrative coun­ties or parts of counties of the mainland, but the Isle of Man in the Irish Sea and the Channel Islands between Great Brit­ain and France have a large measure of administrative auton­omy and are not part of England, Wales or Scotland.

The total land area of the United Kingdom(excluding inland water) is 93,018 square miles. Care must be taken when studying British statistics to note whether they refer toEng­land, toEnglandandWales(considered together for many administrative and other purposes), to Great Britain, which comprises England,Wales and Scotland, or to the United Kingdomas a whole.

The latitude of 50° North cuts across the southernmost part of the British mainland (the Lizard Peninsula) and lat­itude 60° North passes through the Shetland Islands. The northernmost point of the Scottish mainland, Dunnet Head, is in latitude 58°40′. The prime meridian of 0° passes through the old Observatory of Greenwich (London), while the east­ernmost point of England is nearly 1°45′ East and the west­ernmost point of Ireland is approximately 10°30′ West.

The seas surrounding theBritish Islesare very shallow — usually less than 50 fathoms (300 feet) — because the is­lands lie on the continental shelf. To the north-west along the edge of the shelf the sea floor plunges abruptly from600 feetto3,000 feet.

Geology and Topography. Despite their small area, theBritish Isles contain rocks of all the main geological periods. In Great Britain the newer rocks, which are less resistant to weather, and have thus been worn down to form low land, lie to the south and east, and the island can therefore be divid­ed roughly into two main regions, Lowland Britain and High­land Britain.

In Lowland Britain the newer and softer rocks of southern and easternEnglandhave been eroded into a rich plain, more often rolling than flat and rising to chalk and limestone hills, but hardly ever reaching a thousand feet above sea level. The boundaries of this region run roughly from the mouth of the Tyne in the north-east of England to the mouth of the Exe in the south-west.

Highland Britain comprises the whole of Scotlandas well as the mountains of the Scottish Highlands(which extend from the Forth-Clyde valley to the extreme north-west), the Lake District in north-westEngland, the broad central upland known as the Pennines, almost the whole of Wales, and the south-westernpeninsulaofEnglandcoinciding ap­proximately with the counties of Devon andCornwall. High­landBritaincontains all the mountainous parts ofGreat Britainand extensive uplands lying above one thousand feet. This high ground, however, is not continuous but is inter­spersed with valleys and plains.

Britain’s complex geology is one of the main reasons for its rich variety of scenery found within short distances, particularly on the coast. The ancient rocks of HighlandBritainoften reach the coast in towering cliffs; elsewhere the sea may penetrate in deep lochs, as along much of the west coast ofScotland. Even around Lowland Britain there are striking contrasts. In some parts the soft, white limestone — the chalk — forms the world-famous white cliffs of Dover or the Needles off the Isle of Wight; while other parts of the south and south-east coastline have beaches of sand or shin­gle. The eastern coast ofEnglandbetween the Humber and theThamesestuary is for the most part low-lying, and for hundreds of years some stretches of it have been protected against the sea by embankments. These have occasionally been breached, as in the flood disaster of January, 1953, which was caused by violent gales and exceptionally high tides.

The marked tidal movement around theBritish Islessweeps away much of the sand and mud brought down by the rivers and makes the estuaries of the short British rivers valuable as natural harbours.

Climate and Weather. TheBritish Isles lie, throughout the year, in the belt of westerly winds. Thus the prevailing winds blow from a westerly and especially a southwesterly direction, reaching the British Isles from over the vastAt­lantic ocean, and depositing a plentiful rainfall.

It is often somewhat incorrectly said that the British Isles are bathed by the warm waters of theGulf Stream. The Gulf Stream after emerging from the Gulf of Mexico, sweeps along the shores ofFloridaand is truly a stream of warm water a few miles wide. But this water gradually spreads out and drifts towards the north-east across theNorth Atlantic Ocean, being helped by the prevailing south-west winds. The waters of this North Atlantic or the Gulf Stream Drift sweep round the British Isles to spread out over the shallow North Sea and drift past the coast ofNorway. They would not feel warm, however, to anyone attempting to bathe in them even in the summer, and it is not really the water which keeps the climate of theBritish Islesrelatively mild. The water, on its way across theAtlantic Ocean, helps to raise the temperature of the winter winds blowing over it and it is the warmed south-west winds which keep the win­ter climate mild as well as moist. In summer the effect of the ocean waters and the winds is to prevent the climate becom­ing very warm.

One of the most striking things about theBritish Islesis the rapidity with which the weather changes from day to day or even during the day. A warm sunny day may be followed by one with cool or cold dry winds.

BecauseBritainhas rain in every month of the year most of the rivers are well supplied with water. Although rivers are not now much used for navigation, they once afforded the chief highways into the country. Many towns and cities, includingLondon, draw all or part of their water supply from the rivers, and those that rely on reservoirs in the hills have also little fear of serious shortage. Although ports such asLondonon the Thames,Newcastle-upon-Tyne, andGlasgowon theClydeare tidal, and the rise and fall of the tide helps to keep the mouths of the rivers free from silt, the con­stant flow of river water is important. Because of the good rainfall there are still many parts of the country liable to serious flooding.

As much of the weather of theBritish Islesis due to At­lantic influences, the west is wetter than the east and is made wetter still by the presence of most of the highland masses in the west, which cause the air to rise and so to become cooled and lose much of its moisture as rain. Much of the east lies in the “rain-shadow” area, receiving most of the rainfall during the passage of depressions and thunderstorms. No part of theBritish Isleshas normally too little rainfall for cultivation, but many parts have too much. Rain falls in theBritish Islesin every month of the year, with usually least in spring.

In winter the continent of Europe gets colder with increas­ing distance from the Atlantic and a similar effect is notice­able in the British Isles, for eastern Britain faces the colder continent whereas western Britain faces the relatively warm Atlantic. The coldest parts of all are the lofty Highlands of Scotland, but the western shores of the Highlands although wet and bleak are never very cold and Cape Wrath shows about the same January mean temperature as theIsle of Wight. In January the warmest parts of the British Isles are south­westernIrelandand south-westernEngland(Devon andCornwall). There snow is rare and it never lies on the ground for long. Many plants can grow there which would be chilled by frost in other parts of the country. The spring, too, comes earlier.

In summer the south-eastern part ofEnglandis warmest, and it becomes gradually cooler towards the north and north­west, so that the Shetland Islands are the coolest part of theBritish Isles. Some crops which ripen well in the south (wheat, for example) will not ripen in northernScotland.

Latitude clearly has a good deal to do with this but the location of the warmest area at this season — round London — should also be related to the wider expanse of land in the south-east and to distance from the cooling effect of the Atlantic Ocean.

Soil and Vegetation. Many parts of the surface of High­land Britain have only thin, poor soils, with the result that large stretches of moorland are found over the Highlands of Scotland, the Pennines, the Lake District, the mountains of Wales and in parts of north-east and south-west England. In most areas the farmer has cultivated only the valley lands and the plains where soils are deeper and richer.

With its mild climate and varied soils,Britainhas a di­verse pattern of natural vegetation. When the islands were first settled,oak forestprobably covered the greater part of the lowland, giving place to extensive marshlands, thin forests of Scots pine on higher and sandy ground and perhaps some open moorland. In the course of the centuries nearly all the forests have been cleared and woodlands now occupy only about 7 per cent of the surface of the country. MidlandBritainappears to be well wooded because of the numerous hedgerows and isolated trees. The greatest density of wood­land occurs in the north and east ofScotland, in some parts of south-eastEnglandand on the Welsh border. The most common trees are oak, beech, ash and elm and, inScotland, pine and birch.

There are various types of wild vegetation, including the natural flora of woods, fens and marshes, foreshores and cliffs, chalk downs and the higher slopes of mountains; the most widespread is that of the hilly moorland country. Most ofBritain, however, is agricultural land, of which about a third is arable and the rest pasture and meadow.

Farming land is divided into fields by hedges or stone walls and, especially in the mixed farms which cover most of the country, presentsa pattern of contrasting colour. The cool temperate climate ofBritainand the even distribution of rainfall ensure a long growing season; streams rarely dry up, grassland is green throughout the year and full of wild flowers from spring to autumn; there is scarcely a month in which some flowers may not be found in hedgerows and sheltered woodland glades.

Fauna. The fauna of the British Isles is in general similar to that of north-western Europe, though there are fewer species. Some of the larger mammals, including the wolf_T the bear, the boar and the Irish elk, have become extinct; there are foxes in most rural areas, and otters are found along many rive^rs and streams. Both common and grey seals may be seen on various parts of the coast, though not usually in the same localities. Smaller mammals include mice, rats, hedgehogs, moles, squirrels (the imported grey more numer­ous than the native red), hares, rabbits, weasels and stoats.

There are about 430 species of birds, including many song­birds. About 230 species are resident and the rest are regular visitors toBritain. The chaffinch and the blackbird are prob­ably the most numerous and widely and evenly distributed, but sparrows usually predominate near houses, and flocks of starlings, which gather at certain seasons, sometimes con­gregate inLondonand other large towns.

The many species of gulls and other sea-birds which nest round the coast often fly far inland in search of food or shel­ter in rough weather. Many of the rarer species of birds are protected by law.

River and lake fish include salmon, trout, sea-trout, perch, roach and pike.

There are more than 21,000 different kinds of insects, most of them small, in theBritish Isles.

The insect fauna in Britainis less varied than that of continental Europe and lacks a number of common Euro­pean species.

From Britain. An Official Hand­book. 1960; Geography for Today by L. D. Stamp