JOHNSTON'S PHYSICAL ATLAS. *
monsoons and the trades, or the seemingly irr pests, drawn from Reid's Law of Storms ; the world and of Europe complete the meteor sion of Natural History contains the most n dere the most elaborate maps. The firs tributiou of plants, the second that of c Warded plants, three Maps are devoted to animals, one to birds, one reptiles, and two to man; the ethnography of the world and of the Br' h Isles forming the ethnographic
diaramshe mod• e in which the results o these subjects are impressed upon the mind through the eye, is ver various in their combinations. The elements principally consist of II
hasnomena. By Alexander Keith Johnston, F.R.0.8., the edition in imperial folio' for the use of colleges,. by BlitokwOOd and Sons. GEOGRAPHY is primarily concerned with the position and names of places ; but as man makes ports and builds cities, as nature has formed mountain and other phrenomena and continues to grow woods, it was all but impossible to confine the science to latitude, longitude, and a simple nomenclature. Mr. Croker and some imitators have of ,late years reduced geography to a naked state, and given the tyro nothing but. names, by way of a " whet " to begin with; but most writers have com- bined historical and statistical geography with geography proper. The appearance and productions of the country, the manufactures of the people,. with their numbers, manners, and customs, the form of government, and. sometimes institutions and statistics, have long been introduced ; till, What with natural, historical, political, statistical, and social geography, some of the works have almost become encyclopredias of "nature an4 of nations."
From the necessity of the case, such books have always been compila- tions, but frequently done with pains and skill. The existing knowledge, whether derived from philosophet% or travellers, has been cleverly brought together, to form even an interesting book ; and those who take any plea- sure in literary history will find that the larger and more ambitious Works on geography in former times were done as well as in the present day, regard being had to literary ;odes and scientific means. The handsome and elaborate work before us does not essentially differ from former compilations as respects the application of existing knowledge. Neither does its originality lie in the conception of the plan the first idea of which originated with Humboldt, as Berghaus developed. it to a considerable extent in his Atlai. The merit of Mr. Johnston lies in the completeness with which he has carried the plan into execution', and, the liberal boldness which has given the character of enterprise to a publishing speculation. Like former compilers, Mr. Johnston has brought together floating or scattered knowledge. If others have made use of the discoveries of modern Science (as they undoubtedly have) to raise and extend geographical studies, Mr. Johnston is the first in this country who has applied the cycle of sciences to this purpose, and applied it com- pletely, not merely in general range but in particular degree. Weliave even in this new and smaller edition-1. Geology, illustrated under five, divisions ; 2. Hydrography, under six ; 3. Meteorology, under four ; 4. Natural History, under nine,' embracing the natural distribution not only of plants and animals but of man himself.
The mode of this exhibition of scientific phienomena connectedvg th the ..
"great globe and all that it inhabit" is even more striking an, °ye)/ than the collection of the scientific results. In a series of 40 dis,!- anguished first by great clearness, and next by great beautY,Of,,ce ,e3tfn- 'that,. the theoretical and practical conclusions of the four SelelfOit we have enumerated arc presented to the eye in a pithy couP-d'tell. 1 The Maps are as numerous as the subdivisions -,Mst, mentioned ; >tlt is four-and-twenty, with an additional frontispieke4hibiting the 'l and palmontology of the British Isles. Ild&tv0 4 great 1 ikt n or AS., the series, are displayed the geological stiliquibilf ,Ilobe, A an- tain chains of Europe, Asia, and Nineite4t.„.,ai01.114. litlilfr• WO system of the Alps=a' very beautiful Oath, 'and:4 Canic action—the frontispiece coming tinder Arist§' ,. 0' , ,, -on devoted to Hydrography exhibits the burientS And tides , Ole and of particular regions, with the river syStenia of Europill'‘'.4lais,".and .Ame- rice. Humboldt's method of Marking the degrees eii; iltilliffiert4 and winter's cold, and the average temperature of plasbeis, by Ititickys. , of isothermal lines, occupies one map. in Meteorology.' 11 soccittd ,.. 'marks " the currents ef air "-; that is, the course of sufzh regular winds rib) the , lar hurricaniCandtem- while two rampmaps of ogical seotion. TheAvi‘ merous, and except the ea- xhibite the geogaphioat is-
shading, and colours. The course of the great currents of the oceavfor example, is marked by an outline and by slight shadings, which giv to a uniform tint the effect of variety of colouring. The mountain-c ins are exhibited by black lines of varying
The Physical Atlas of ;gator ' F.G.S., tic. &c. Reduced fro Academies, and Families. thickness ; the prettiness of the usual relief being sacrificed to distinct- ness. The natural distribution of plants is shown by typical trees,, and by variety of colours with references. The rain map impresses itself by shadows, the shading being deeper in proportion to the quantity of rain that falls; the rainless districts, especially of the Great Sahara Arabia, parts of Persia, Belooehistan, and Central Asia, standing fully out in white paper, and forcing an idea of their extent upon the merest looker- on. Other and more usual means are adopted. far details,—as arrows, simple lines, figures, and common colouring.
We have dwelt thns upon the maps and. their execution because they form in reality the principal feature of the work ; be the letterpress which accompanies them should not pass without praise. Its primary object is of course to point out the uses, and explain in detail the mode of using each particular map; but it does a good deal more than this. The principles of the subject are compendiously expounded, and what may be called its leading statistics fully exhibited. Much., of course, is put into it form that is best adapted for the explanation of the maps ; but this is aceffiental. So fir as the letterpress admits of separation from the plates, it could be advantageously studied by itself as a compendious view of the natural phanomena of the world. The Glaciers, for example, is not an uncommon subject ; hut this is the best and most compact oak/relation of them we have seen.
"A glacier may be. compared to an icicle depending from the snow-covered roof of a cottage, which, gradually becouriung thawed by the suds heat, conveys the water of the melted snow in a trickling stream to the ground. below. In those high mountains which extend beyond the line of perpetual eongelation, a con- siderable part of their summits is covered with snow during the whole year. The glacier commences at the base of this snow line, and extends downwards somewhat like the icicle we have just compared it to, occupying the hollow ravines on the sides of the mountaiu, and extending into the valleys, sometimes from one to two thousand feet below the situation of the snow line. The epees part of the glacier consists of a. mass of consolidated and partially melted snow, which is called by- the French 'lire, or firm by the German Swiss. Between this mass and the true. glacier there is often interposed a precipice, over which the snow is as it were shot, and below this the-real glacier commences. The glacier consists of a vast mass of half-melted ice' which is slowly pmpelled. along the whole length of the ravine, until it comes to the plain, where from its. foot a stream of water issues. Along the whole length of the glacier there are a series, of clefts or cracks, crossing the length of the mass in a waving manner, summing & curve forwards in the centre of the mass' but towards the edges running more pendia These. waving fissurel indicate the onward motion of the aluggish mass, and are rendered more conspicuous by bands of harder ice, caused by the infiltration of water; the edges of which band; rising up above the surface, collect sand and earth in the hollows. The edges of the glacier, as .well as- the ground on each side are covered with a mass of fragmentary rocks and sand, which the icy street; detaches and carries along in its progress.: them are called moraines.
"It has now been ascertained, that the glacier in its. motion obeys the laws which are proper Ma semi-liquid fluid,.such as that of which it is composed ; and that this motion Fs inffnenced chiefly by the degree of heat, causing a more or lees rapid Ilimefaction, anti by the declivity of' the ground' over which the mass moves. Thus the motion is continuous 'and progressive, but greater in summer than in winter, and greater during' the day than during the night The' centre of the mass moves always faster thaw the sides, and it is. probable the to moves faster than the bottom. Ther velocity of movement„ all other circumstances being, alike, increases with the increase of the slope. The greatest summer velocity of the glacier in some places is about four feet in the twenty-four. hours, and in other places it is' only about eight or nine' inches En Europe the principal glacier mountains are thn Alps. Front their ever-flowing- streams several of the largest European rirera take their rise especially these on the Northern sidled the Alps.. Althougle the Pyrenean mountains extend, beyond the line of perpetual snow yet no true glaciers have been discovered in that great range. In Norway and Spitsbergen, glaciers are abundant and' of great extent"'
Again, how comprehensive and. clear is this general view of the tides of the world
"The source of the tides is, therefore, to be sought in the greatre.servoir of ocean sound theSauthern Pole. This- polar reservoir is agitated on opposite sides by gs)a Moon in its alternate lower and upper transits, and by the Sun braless de- it s*, Ilere the great central agitation seems to commence; and hence on all-sides the In to flow Northward. From the South Pole thiagreat agitation flows into. Ocean; and, proceeding Northward, the great tide-wave strikes with on the shores of Hindostan, and finally breaks in the months of the where- it expends its force on the shores in the form of the well-known destroying Btu, South; in like m axle& out by in itsuirriads of hap, horizontally- acting rupted bottom only Ms only the small wa an action like the tide, propagated. ommsupenici, submarine work; and America, whet; diffused, a tlfrauglt the more open parts the North Path& we have is
a Bay of Fundy. * marnow bemsefai to fo. aa indicated by the Chart of the
waters of the Antarctic Ocean—that have passed. over the- mass of waters Zealand, and.the South Pole, aud, direction of the resultant forces—we and moving to the North. and West, tion thus communicated to this mass moving ridge of waters, which cannot pushing' before it other muses of water, to which all its.foree is finally imparted.. In rated travels Northward and. Westward, long ceased to sot on the first mass of water. The we
violent Games, and tend
the,south c bore of the. Hoogly. The Atlantic,, in the like manner, receives from. pesseeity, sOn reservoir itsgroet wave of tide; which passes Northward: with. inn. where again\nd expends its forces on the shores of Britain and North America; becomes the. enormous stream-tide of the Bristol Channel and' the of the Bay of Fundy, so well known to all mariners. From the ner, the Pacfficabould receive its great tide, were it not barri- erIblemalimarine steppes, and itsthousand coral reefs, and. island; to whose calm seas MI propagation of this, great ave can gain access.. It is by depth and uninter- hat a great wave like the tide can forte entrance: , raised by a local tempest, that tnivel.over the surface;. nding-uniformly to all depths of the ocean, cannot be coating abme. Thor tides are built out of the Pacific by it alone and. with difficulty by the Eastern side of rapidly diminishing, the tide extends a.certain way.
• of the sea, continually diminishing in intensity. In
er the bores of 'a Hbogly nor the. terrific tides of • the phenomena of .the saceession, of the tides; us take the spring-tider or larg Commencing with new or fait moon, let of San and Moon. Let us oonceivai Ude formed by the coincidence of the actions that this joint action has taken effect on the e lummanes, in conjunction. or opposition, ug- East from Van Diemen's Land; New communicated tte them motion- in the all manifestly have a mass elevated following the luminaries. The. me- water has raised a large mass, or spend its forces acquired, but by cl raising them too in a wave, his way the wave originally gene- tar the bodies generating it have of. the Sun and Moon on Monday morning, and e generated during the transit of Van Diemen's Land at twelve, has by noonnea4c4....mg high-water on the coast
peninsula of Hindostan, and at one afternoon is at the reached the point of the
it enters the Atlantic, and, travelling Northwards, brings high-water at the same hours to the Western coasts of Africa and the Eastern shores of America."
The use of the volume is not however, confined to imparting and mi. pressing scientific knowledge. Wherever the subject admits of it, science is turned to practical account, especially for the purposes of the navi- gator. The following facts on currents is an indication. "From our present knowledge of the rapidity of currents, we may estimate that, supposing a molecule of water to return to the same place from which it de- parted, it would require a period of two years and ten months to compkte the circuit of 3,800 leagues. A boat, which may be supposed to, receive no impulse from the winds, would. require thirteen months from the Canary Islands to reach Caracas, on the coast of Venezuela; ten months to make a tour of the Gulf of Mexico, and reach Tortoise Shoals, opposite Havana ; while forty or fifty days might be sufficient to carry it from the Strait of Florida to the bank of New- foundland. At a time when the art of navigation was in its infancy, the Golf Stream furnished the genius of Christopher Columbus with certain indications of the existence of Western regions. Two corpses, the features of which indicated '5 race of unknown men, were thrown on the coast of the Azores, towards the end of the fifteenth century. Nearly at the same period the brother-in-law of Columbus, Peter Correa, Governor of Porto Santo; found on the strand of this island pieces of bamboo of an extraordinary size, brought thither by the Western currents. When the wind has been long from the West, a branch of the stream runs with considerable force in a North-easterly direction, towards the coasts of Europe. By this the fruit of trees belonging to the torrid zone of America is annually cast ashore on the Western coasts of Ireland and Norway; and the seeds of plants which grew in Jamaica, Cuba, and the adjacent continent, are collected on the shores of the Hebrides. Thither, also, barrels of French wine, the remains of vessels wrecked in the West Indian seas, are carried. In 1809, H. M. S. Little Belt was die. masted at Halifax, Nora Scotia, and her bowsprit was found eighteen months after in the Basque Roads; and the mainmast of theTilbury, burnt off lhspaniola, in the Seven Years War, was brought to our shores. "The trade routes, or lines of navigation which experience has proved to be the most advantageous in communicating between the different parts of the globe, are pointed out by coloured lines on the following charts. The first element for determining their routes is the state of the wind, the limits and directions of which are explained in the division Meteorology, Pints 2. Next to these the ocean currents are most important; and, in proportion as our acquaintance with them has increased, the tracks which vessels ought to follow, in sailing from one country to another, have become better known and moro precisely fixed. The influence of ocean currents in navigation v be understood front a fact men- tioned by Colonel Sabine, that, on his voyage fromSierra Leone to New York, he made almost a fourth part of the route by thew assistance: of 9,000 miles through which he sailed, the ship was carried. 1,600 miles by currents. And Lieutenant Maury, in reference to his valuable series of charts, now publishing, states, that very recently a fine frigate took a hundred days to sail from the Ueited States to Eioslaneiro, whilst another vessel, which left at the same time, performed the some voyage, by the aid of the chart of the currents, in thirty days."
Notwithstanding the size and costliness of this volume, it is only an abridgment of a larger work, with the plates reduced and several sections omitted, as better fitting the publication for the use of "colleges, academies, and families." That original work we have not seen, but we believe it was considered a wonder of typographical and map engraving. It elicited the warm praises of liumbokit„. of Leopold. Von Bitch, of Brewster, of Whewell, Mrs. Somerville, and. other eminent persons; Geographical Societies have praised and honoured its author ; what is more than all, perhaps; the Admiralty have officially given die book countenance and encouragement.