Account of the Great Speckled Diver or Loon. From White's Naturalifts Calendar. AS one of my neighbours was traverfing Wolmer foreft from Bramfhot across the moors, he found and the heat communicated is in every cafe proportional to the quantity of abforption. It appears, from fome ingenious experiments of M. Bouguer, that we receive only four-fifths of the rays of a vertical fun; and when that luminary approaches the horizon, the portion of this light, which reaches the furface of the earth, is much fmaller. Thus, at an elevation of 20 degrees, it is one-half; at that of 10 degrees, one-third; and at that of five degrees, one-eighth. Hence, the fun-beams are moft powerful on the fummits of lofty mountains, for they suf. fer the greatest diminution in paffing through the denie air of the lower regions. If the air derived its heat from the furface of the earth, thofe countries would be warmest which enjoyed the greatest quantity of fun-fhine. The British islands are fhrouded in clouds nine months of the year; yet our climate is milder than that of the fame parallel on the continent, where the sky is generally serene. The ele vated town of Quito, expofed to a brilliant fun, enjoys a temperate air; while the Peruvian plains, fhaded with fleecy clouds, are parched with heat. Were the reatoning in the text to be admitted, we should conclude, that the tops of mountains are warmer than their bafis. To fay that air, much rarefied, is not fuícep tible of heat, is a very extraordinary affertion, fince we are acquainted with no fubftance whatever that may not be heated Befides, a more intenfe cold may be artificially produced than what prevails in the lofty regions of the atmosphere. We must recur to other principles for the true folution of the fact. It is indiffe. rent what portion of the air first receives the heat; the effect depends entirely on the nature of its diftribution. If the atmosphere were of an uniform denfity throughout, the heat would, at all heights, be likewife the fame. But as the den fity varies according to the anitude, the uittribution of heat is affected by that circumstance, and follows a certain correfponding law. I would gladly develope the principles from which this theory is deduced, but the popular nature of the prefent treatife forbids all abftract difcuffion. I fhall therefore, content myself with gi ving a table of the diminution of heat at different altitudes. Diminion of heat, in degrees of 120 Altitude in feet. 3,000 6,000 9,000 12,000 15,000 18,000 The diminution of heat, on the afcent, is not quite fo great in extensive continents; for the intercourfe between the rare and the denfe portions of the atmofphere is, in this cafe, neceffarily flow, and the heat, which is principally formed at the furface, will only be partially difperfed. It is a common mistake to suppose, that the same heat obtains, at a certain depth, in every part of the globe. The fact is, that heat, originally derived from the fun, is communicated very flowly to the matter below the furface, which, therefore, does not feel the viciffitude of feafons, but retains the average temperature of the climate for many ages. Hence the utility of examining the heat of fprings which is the fame with that of the substances through which they flow. The found a large uncommon bird fluttering in the heath, but not wounded, which he brought home alive. On examination it proved to be Colymbus glacialis, Linn: the great fpeckled diver or loon, which is most excellently defcribed in Willoughby's ornithology. Every part and proportion of this bird is fo incomparably adapted to its mode of life, that in no inftance do we fee the wifdom of God in the creation to more advantage. The head is sharp, and fmaller than the part of the neck adjoining, in order that it may pierce the water; the wings are placed forward and out of the center of gravity, for a purpose which fhall be noticed here after; the thighs quite at the podex in order to facilitate diving; and the legs are flat, and as tharp backwards almoft as the edge of a knife, that in ftriking they may easily cut the water; while the feet are palmat ed, and broad for fwimming, yet fo folded up when advanced forward to take a fresh ftroke, as to be full as narrow as the thank. The two exterior toes of the feet are longeft; the nails flat and broad refembling the human, which give ftrength and increafe the power of fwimming. The foot, when expanded, is not at right angles to the leg or body of the bird: but the exterior part inclining towards the head forms an acute angle with the body; the intention being not to give motion in the line of the legs themselves, but by the combined impulse of both in an intermediate line, the line of the body. Moft people know, that have obferved at all, that the fwimming of birds is nothing more than a walking in the water, where one foot fucceeds the other as on the land; yet no one, as far as I am aware, has remarked that diving fowls, while under water, impel and row themfelves forward by a motion of their wings, as well as by the impulfe of their feet: but fuch is really the cafe, as any perfon may easily be convinced who will obferve ducks when hunted by dogs in a clear pond. Nor do I know that any one has given a reafon why the wings of diving fowls are placed fo forward: doubtlefs, not for the purpose of promoting their speed in flying, fince that pofition certainly impedes it; The following table exhibits the average heat of places on the level of the fea, computed by the celebrated aftronomer, profeffor Meyer, for every five degrees of latitude. 45 62 58 ༡༠ 32 By comparing this table with the preceding, it is eafy to discover, for any latitude, the altitude of the curve of congelation, or where the average temperature is 320.-E. E. but but probably for the increase of their motion under water, by the ufe of four oars inftead of two; yet were the wings and feet nearer together, as in land birds, they would, when in action, rather hinder than aflift one another. This Colymbus was of confiderable bulk, weighing only three drachms thort of three pounds avoirdupois. It measured in length from the bill to the tail (which was very thort) two feet; and to the extremities of the toes four inches more; and the breadth of the wings expanded was 42 inches. A perfon attempted to eat the body, but found it very ftrong and rancid, as is the fleth of all birds living on fish. Divers or Loons, though bred in the most northerly parts of Europe, yet are feen with us in very fevere winters; and on the Thames are called fprat loons, becaufe they prey much on that fort of fith. The legs of the Colymbi and Mergi are placed fo very backward, and fo out of all center of gravity, that thefe birds cannot walk at all. They are called by Linneus compedes, becaufe they move on the ground as if fhackled, or fettered. Contrafts and Confonancies between Animals and the Earth. From Dr. Hunter's Tranflation of St. Pierre's Studies of Nature. THERE is feen, on the fhores of India, a large and beautiful bird, white and fire-coloured, called the Flamingo, not that it is of Flemish extraction, but the name is derived from the old French word flambant, (flaming) because it appears, at a diftance, like a flame of fire. He generally inba bits in fwampy grounds, and falt marshes, in the waters of which he conftructs his neft, by railing out of the moisture, of a foot deep, a little hillock of mud, a foot and a half high. He makes a hole in the fummit of this little billock; in this the hen depofits two eggs and hatches them, with her feet funk in the water, by means of the extreme length of her legs. When feveral of thefe birds are fitting at the fame time on their eggs, in the midft of a fwamp, you would take them, at a difiance, for the flames of a conflagration, bursting from the bofom of the waters. Other fowls prefent contrafts of a different kind on the fame fhores. The pelican, or wide throat, is a bird white and brown, provided with a large bag under its beak, which is of exceffive length. Out he goes every morning to ftore his bag with fifh: and, the fupply of the day having been accomplished, he perches on fome pointed rocks on a level with the water, where he ftands immoveable till the evening, fays father Du Tertre *, " as in a ftate of profound forrow, with the head drooping, from the weight of his long bill, and eyes fixed on the agitated ocean, as motionless as a itatue of marble." On the duiky ftrand of thofe feas may fre quently be diftinguished herons white as fnow, and in the azure plains of the tky, the paillencu of a very white, fkimming through it almoft out of fight: he is fometimes glazed over with a bright red, having likewife the two long feathers of his tail the colour of fire, as that of the South-Seas. In many cafes, the deeper that the ground is, the more brilliant are the colours in which the animal, deftined to live upon it, is arrayed. We have not, perhaps, in Europe, any infect with richer and gayer cloathing than the fiercoraceous fcarab, and the fly, which bears the fame epithet. This latt is brighter than burnished gold and fteel; the other, of a hemifpherical form, is of a fine blue, inclining to purple and in order to render the contraft complete he exhales a firong and agreeable odour of musk, Nature has beftowed at once, in the colours of innoxious animals, contrafts with the ground on which they live, and confonances with that which is adjacent, and has faperadded the inftinct of employing thefe alternately, according as good or bad fortune prompts. Thefe wonderful accommodations may be remarked in most of our fmall birds, whofe fight is feeble, and of thort duration. The gray lark finds her fubfittence among the grafs of the plains? Does any thing terrify her? She glides away, and takes her ftation between two little clods of earth, where he becomes invifible. On this poft fhe remains in fuch perfect tranquillity, as hardly to quit it, when the foot of the fowler is ready to crush her. The fame thing is true of the partridge. I have no doubt that thefe defenceless birds have a fenfe of thofe contrafis and correfpondencies of colour, for I have remarked it even in infects. In the month of March laft, I obferved, by the brink of the rivulet which washes the Gobelins*, a butterfly of the colour of brick, repofing with expanded wings on a tuft of grafs. On my approaching him, he flew off. He alighted, at fome paces diftance, on the ground, which, at that place, was of the fame colour with himself. I approached him a fecond time; he took a second flight, and perched again on a. fimilar ftripe of earth. In a word, I found it was not in my power to oblige him to alight on the grafs, though I made frequent attempts to that effect, and though the paces of earth which feparated the turfy foil were narrow, and few in number. This wonderful inftinct, is, likewife, confpicuously evident in the cameleon. This fpecies of lizard, whofe motion is extremely flow, is indemnified for this, by the incomprehenfible faculty of affum ing, at pleafure, the colour of the ground over which he moves. With this advantage, he is enabled to elude the eye of his purfuer, whole speed would foon have overtaken him. This faculty is in his will, for his fkin is by no means a mirror. It reflects only the colour of objects, and not their form. What is farther fingularly remarkable in this, and perfectly afcertained by naturalifts though they aflign no reafon for it, he can affume all colours, as brown, gray, yellow, and especially green, which is his favourite colour, but never red. The cameleon has been placed, for weeks together, amida fearlet fluffs, without acquiring the * A small village in the suburbs of Paris, noted for its manufactures in fine tapestry, and fibçib mirogs. flightest flighteft fhade of that colour. Nature feems to have with-held from the creature this fhining hue, becaufe it could ferve only to render him perceptible at a greater diftance; and, farther, because this colour is that of the ground of no fpecies of earth, or of vegetable, on which he is defigned to pats his life. But, in the age of weaknefs and inexperience, nature confounds the colour of the harmless animals, with that of the ground on which they inhabit, without committing to them the power of choice. The young of pigeons, and of moft granivorous fowls, are clothed with a greenish fhaggy coat, refembling the moffes of the nets. Caterpillars are blind, and have the complexion of the foliage, and of the barks, which they devour. Nay, the young fruits, before they come to be armed with prickles, er inclosed in cafes, in bitter pulps, in hard fhells, to protect their feeds, are, during the feafon of their expantion, green as the leaves which furround them. Some embryons, it is true, fuch as thofe of certain pears, are ruddy or brown; but they are then of the colour of the bark of the tree to which they belong. When those fruits have inclofed their feeds in kernels, or nuts, fo as to be in no farther danger, they then change colour. They become yellow, blue, gold-coloured, red, black, and give to their refpective trees their natural contrafts. It is ftrikingly remarkable, that every fruit which has changed colour has feed in a state of maturity. It is in the countries of the North, and on the fummit of cold mountains, that the pine grows, and the fir, and the cedar, and moft part of refinous trees, which helter man from the fnows by the closenefs of their foliage, and which furnith him, during the winter feafon, with torches, and fuel for his fire-fide. It is very remarkable, that the leaves of those ever. green trees are filiform, and are extremely adapted, by this configuration, which poffeffes the farther advantage of reverberating the heat, like the hair of animals, for refiftance to the impetuofity of the winds, that beat with peculiar violence on elevated fituations. The Swedish naturalifts have observed, that the fatteft pines are to be found on the dryeft and moft fandy regions of Norway. The larch, which takes equal pleasure in the cold mountains, has a very resinous trunk. Mathiola, in his ufeful commentary on Diofcorides, informs us, that there is no fubftance more proper than the charcoal of these trees, for promptly melting the iron minerals, in the vicinity of which they peculiarly thrive. They are, befides, loaded with moffes, fome fpecies of which catch fire from the flighteft fpark. He relates, that being obliged, on a certain occafion, to pafs the night in the lofty mountains of the Strait of Trento, where he was botanizing, he found there a great quantity of larches (larix) bearded all over, to ufe his own expreffion, and completely whitened with mofs. The thepherds of the place, willing to amufe him, fet fire to the moffes of fome of these trees, which was immediately communicated with the rapidity of gun-powder touched with a match. Amidst the obfcurity of the night, the flame and the fparks feemed to afcend up to the |