The sun is the great fountain of heat, which is very differently apportioned (ALr the surface of our globe. The annual quantity which any place receives, being compounded of the force and duration of the solar beams, depends therefore altogether on the latitude. But the subsequent diffusion of that heat is performed by the agency of the atmosphere, which, encircling the earth with its irregular, yet incessant motions, blends the op posite extremes, and tempers to a considerable degree the original inequalities of climate. Whether the calo rific impressions are directly made on the surface, or absorbed in the clouds, or spent among the foliage of the lofty trees, it hence matters little; since they must ultimately be communicated to the ground, and be min gled in the common store. Whatever serves to facilitate the motion of air along the surface, must have an in fluence to equalize, in some degree, the vicissitudes of the seasons. The progress of cultivation, therefore, in a new country, can have no real effect in changing the mean temperature ; but, by removing the obstacles to the free passage of the wind, it may contribute to soften the roughness of the climate, and diminish the exces sive distance between the heat of summer and the cold of winter.
If the motions of the air were quite instantaneous, an uniform temperature would have been maintained over the whole surface of our globe. The imperfect mobility of that fluid, and the remoteness of the poles from the equator, prevent the inequality of the sun's action from being completely corrected, and occasion all that gradation of climate which marks the successive zones.
But the commixture of the higher and lower strata of the atmosphere is a process incomparably easier, than what is effected by the transfer and interchange of the heated portions of air in the vast extended line between the north and the south. The region of clouds no where, perhaps, exceeds five miles in height, while the distance of the poles from the equator is more than six thousand miles. Every part of a perpendicular co lumn of air has, therefore, an equal share of heat. But though the absolute quantity of heat thus distributed vertically be the same, its apparent intensity is very different, and the temperature of the air, at any elevation, most be inversely proportional to the capacity for heat corresponding to its diminished density. The capacity of atmospheric air, as affected by its density, being, therefore, ascertained from experiment, the decreasing gradation of temperature, at successive heights, may be thence deduced. Winds, blowing from a northern quarter, will cool the surface, and those from the south must warm it. We might presume, that air which has traversed elevated tracts, will descend into the plain impregnated with cold. Yet this notion, so generally received, will appear, on examination, to be unfounded. The air becoming denser in its descent, has its capacity diminished, and consequently the share of heat which it naturally retains, must now indicate a higher tempera ture. But we reserve the full discussion of this impor tant subject for the article CLIMATE. See also ATMOS PHERE, CAPACITY, ELEVATION, and HEAT. (x) III. The Human Species as existing in America.
With the exception of two great nations, of which an account will be given in another part of this work, (See IVIExico and PErtu,) the inhabitants of America, when discovered by the Spaniards, were all in that state to winch the name of savage has been applied; and there was an astonishing similarity in the features of their con dition through the whole of the regions which they in habited. There is an infancy with regard to the human mind, as well as the body. It likewise has its period of imbecility, when its ideas have not been multiplied by education, and when its powers have not been unfolded and strengthened by exercise. This is true, both of nations and of individuals. There is a time when nu merous tribes, and even the people of whole continents, are elevated only a few degrees above the animals, which man in his advanced and cultivated state denomi nates irrational. Their faculties may then be said to be in embryo. Their curiosity is unawakened, and the sphere of all their mental operations is narrow. As yet philosophy has not begun to investigate things human and divine; it is not once enquired by what means we see, or hear, or feel ; reasoning and research are un known; speculation has not learnt to anticipate discove ry; words, the vehicles of thought, are few, and as they are applied to a great number of objects, their import is various. In this state of the human understanding
and attainments, the deficiencies of vocal utterance are supplied by extravagant looks and gestures, and the sa vage communicates his ideas, and expresses his desires, not with his tongue only, but with his whole body.
In the early stages of society, the means of subsist ence alone excite and occupy the attention of man. his thoughts are limited by the severe necessity of his con dition, to his immediate support, and whatever may con tribute to it; and all beyond this either escapes his ob servation or is regarded with indifference. As his ideas are scanty, so his stock of words is small. His bow and arrows, the river and the wood, his friend and his ene my, constitute the vocabulary of his substantives ; and to strike, and to be struck, to rise, and to lie down, to cat, to drink, to sleep, and, to dance, are almost the only verbs, with which he is acquainted. All his notions are individual; he has hardly a conception of a class of ob jects agreeing in some particulars, and yet differing so much, as to be arranged into species, and distributed into varieties. Though a member of a tribe, he cannot perceive its interest as in any degree separated from his own. He never thinks of attending to one quality in a substance, and of excluding the rest from the in tellectual regard. His deities are local, invested with human organs, and represented in terrific shapes ; and the worship which is offered to them partakes of their dreadful character. It is chiefly by examining the lan guage of savage nations, that we can ascertain the de gree of mental improvement which they have reached. They have no words expressive of abstract or general ideas, and no terms by which the operations of the mind are distinguished : their whole phraseology has an im mediate reference to the senses, and is closely associ ated with objects which are without. Duration, exten sion, subject, attribute, unity, divisibility, and a thousand other expressions always to be found in the language of a thinking and a cultivated people, are entirely unknown to them. The character of the American Indians cor responds exactly with these observations. The count less tribes which wander over the plains of Brazil, Pa raguay, and Guiana, or inhabit the banks of the Marag non and Oroonoco, are utterly unacnuaintPd with every thing beyond the preservation of their lives, or the in dulgence of their appetites. Their mental powers art unexercised and dormant; nothing is to be seen anent;; them which implies any each of thought, or ingenuity of contrivance. Not a few of them are destitute of houses or huts, to protect themselves from the inclem ency of the weather, but main in naked wildness from place to place, and follow thenr prey, hardly to he dis tinguished from the brute creation. The people whom Columbus found in the Bahamas, and sonic of the neigh bouring islands, were in a situation not cry difierent. An extreme simplicity, which ran through all their ac tions ; a stupid, staring, and lifeless eye; all ignorance of every thing which should occupy the earliest thoughts of rational beings; an imbecility of mental energy, awl an incapacity for bodily exertion; these, and other cir cumstances equally degrading, struck the Europeans when they first visited America, as descriptive of the Indian race ; and made such an impression upon thehr minds, that they were unwilling to rank them with hu man creatures. This opinion, which the interest and avarice of the settlers contributed to establish, was the cause of much of the cruelty which was exercised against those unhappy people ; and it required a bull from the pope to show that it was false. Nor have the rude inhabitants of America improved in any remarkable degree since the of the western hemisphere. They still remain in all their native ignorance and bar baritv ; and. as is usually the case w ith the uninstructed, they regard themselves as supremely endowed with every qualification which can elevate and dignify the human species; a circumstance which renders their condition only the more truly wretched and deplorable. " Since the time of Columbus and those who followed him," says the elegant Robertson, " persons more en lightened and impartial than the discoverers or conque rors of America, have htld an opportunity of contempla ting the most savage of its inhal.itants ; and they have been astonished and humbled with observing how nearly man, in this condition, approach( s to the level of the brutes." See The Dist. rf ./nicr;ca, vol. i. book iv. p. 344. 12mo.