opposite side of the plate are a number of toothed wheels, each moveable, and turning freely about its own centre. The first to the extreme right has 12 teeth; the second, proceeding from right to left has twenty, and all the others have 10. About each of these wheels an outer rim or circle is described on the surface of the plate, which circle is divided into the same number of equal parts as there are teeth in the wheel which it surrounds, and which is moveable, as it were within it. The figures corresponding to each of these points of division are inscribed on all the fixed circles, commencing with O at that portion of each which is nearest to the extremity of the side of the box on which they are placed, and proceeding round in the direction of from left to right. Passing over at each of these zero points of division, and attached to the surface of the plate, is a small tongue of metal which projects slightly over the enclosed wheel, so as not, however, to rest on or be in contact with it, but simply for the purpose of arresting the progress of the rod held in the hand of the operator, as seen in the preceding illustration, when engaged in imparting motion to any one of the wheels. From the number of teeth which we have given to those wheels, it is evident that the one to the extreme right, which contains 12, is intended for what may be termed a pence wheel; the second, which has 20, for a shillings wheel; the third, which has 10, for the units of pounds; the fourth, for tens; the fifth, for hundreds; the sixth, for thousands; the seventh, for tens of thousands; and the eighth, for hundreds of thousands. By enlarging the machine, this number might be increased, and the power of the instrument extended. We may now proceed to point out the internal arrangement of the machinery. Motion is communicated by the wheel and axis a b, which is furnished with a contrite wheel c. This actuates the next in the series which is placed in the opposite direction. On the same axis are placed two similar wheels de, the last of which gives motion to the wheel and barrel fg. There are two apertures in the upper plate A B, through which the figures on the barrel may be seen, so that the person who moves the wheel a may readily register the amount of motion, by observing the figures as they pass these apertures. b single pound on the divided circle of the next train. The practical object of the calculating engine is to compute and print a great variety and extent of astronomical and navigation tables, which could not otherwise be done without enormous intellectual and manual labour, and which, even if executed by such In the complete machine there are several of these labour, could not be calculated with the requisite actrains of wheels, and they communicate with each curacy. Mathematicians, astronomers, and navigaother by a small lever h, shown in the diagram. Now, tors do not require to be informed of the real value if we suppose the first of these barrels to have made of such tables; but it may be proper to state, for the an entire revolution, the two connecting bars ii, will information of others, that seventeen large folio have raised the lever and moved the communicating volumes of logarithmick tables alone were calculated wheel of the next train one tooth forward in its under the superintendance of M. Prony, at an enorcourse. If, for example, it be the barrel which re-mous expense to the French government; and that presents shillings, it will by this means indicate a the British government regarded these tables to be of such national value, that they proposed to the ]ber 2 (column C); and that the same number will French Board of Longitude, to print an abridgement always recur in that column, which may be called of them at the joint expense of the two nations, and the second difference, will appear to any person who offered to advance £5000 for that purpose. But, takes the trouble to carry on the table a few terms besides logarithmick tables, Mr. Babbage's machine further. Now, when once this is admitted as a will calculate tables of the powers and products of known fact, it is quite clear that, provided the first numbers, and all astronomical tables for determining term (1) of the table, the first term (3) of the first the positions of the sun, moon, and planets; and the differences, and the first term (2) of the second or same mechanical principles have enabled him to constant difference, are originally given, we can conintegrate innumerable equations of finite differences, tinue the table to any extent, merely by simple adthat is, when the equation of differences is given, he dition: for the series of first-differences may be can, by setting an engine, produce at the end of a formed by repeatedly adding the constant difference given time, any distant term which may be required, 2 to (3) the first number in column B, and we then or any succession of terms commencing at a distant necessarily have the series of odd numbers, 3, 5, 7, point. &c.; and again, by successively adding each of these to the first number (1) of the table, we produce the square numbers." On the means of accomplishing this, we need make no apology for quoting Mr. Babbage's own words. "As the possibility of performing arithmet- Having thus thrown some light on the theoretical ical calculations by machinery may appear to non-part of the question, Mr. Babbage proceeds to show mathematical readers too large a postulate, and as it that the mechanical execution of such an engine as is connected with the subject of the division of labour, would produce this series of numbers, is not so far I shall here endeavour, in a few lines, to give some removed from that of ordinary machinery as might slight perception of the manner in which this can be be conceived. He imagines three clocks to be done; and thus to remove a small portion of the veil placed on the table, side by side, each having only which covers that apparent mystery. That nearly all one hand, and a thousand divisions instead of twelve tables of numbers which follow any law, however hours marked on the face; and every time a string complicated, may be formed, to a greater or less ex- is pulled, each strikes on a bell the numbers of the tent, solely by the proper arrangement of the succes-divisions to which the hand points. Let it be supsive addition and substraction of numbers befitting posed that two of the clocks, for the sake of distinceach table, is a general principle which can be de- tion called B and C, have some mechanism by which monstrated to those only who are well acquainted the clock C advances the hand of the clock B one with mathematicks; but the mind, even of the reader who is but very slightly acquainted with that science, will readily conceive that it is not impossible, by attending to the following example. Let us consider the subjoined table. This table is the beginning of one in very extensive use, which has been printed and reprinted very frequently in many countries and is called a table of square numbers. division for each stroke it makes on its own bell; and let the clock B by a similar contrivance advance the hand of the clock A one division for each stroke it makes on its own bell. Having set the hand of the clock A to the division I, that of B to III, and that of C to II, pull the string of clock A, which will strike one; pull that of clock B, which will strike three, and at the same time, in consequence of the mechanism we have referred to above, will advance the hand of A three divisions. Pull the string of C, which will strike two and advance the hand of B two divisions, or to division V. Let this operation be repeated; A will then strike four; B will strike five, and in so doing will advance the hand of A five divisions; and C will again strike two, at the same time advancing the hand of B two divisions: Again pull A, and it will strike nine; B will strike seven, and C two. If now those divisions struck, or pointed at by the clock A be attended to and written down, it will be found that they produce a series of the squares of the natural numbers; and this will be the more evident, if the operation be continued further than we have carried it. Such a series could of course be extended by this mechanism only so far as the three first figures; but this may be sufficient to give some idea of the construction, and was in fact, Mr. Babbage states, the point to which the first model of his calculating engine was directed. Any number in the table, column A, may be obtained by multiplying the number which expresses the distance of that term from the commencement In order to convey some idea of the power of this of the table by itself; thus 25 is the fifth term from stupendous machine, we may mention the effects the beginning of the table, and 5 multiplied by itself, produced by a small trial engine constructed by the or 5 is equal to 25. Let us now substract each term inventor, and by which he computed the following of this table from the next succeeding term, and table from the formula x+x+41. The figures place the results in another column (B), which may as they were calculated by the machine, were not be called first-difference column. If we again sub-exhibited to the eye as in sliding rules and similar stract each term of this first-difference from the suc-instruments, but were actually presented to it on ceeding term, we find the result is always the num-two opposite sides of the machine, the number 383 113 347 743 1301 2021 Leaving these creatures of a day, he turns to immortal man; and here the same variety, and the same design and appropriate conformity of the objects to the end, are exhibited. No two heads are alike; and most nations, and indeed many families, have their own peculiar characteristicks in this respect. Thus in the European, soft, waving, and full, and of a brownish or chestnut colour; the Mongolian and American, stiff, straight, thin, and black; the South sea islanders, soft, thick, curly, and black; the Negro, crisp, frizzled, short, and black. beautiful and economical piece of mechanical conThe anatomist sees in the structure of a hair, a observes, first, that as an appendage to the skin, it trivance. Taking the human hair for example, he While the machine was occupied in calculating this table, a friend of the inventor undertook to write down the numbers as they appeared. In consequence of the copyist writing quickly, he rather more than kept pace with the engine at first, but as soon as five partially participates in its organization. The skin figures appeared, the machine was at least equal in is composed of three layers; the first, or external of speed to the writer. At another trial, thirty-two which, is called the cuticle, or scarf skin, and is numbers of the same table were calculated in the transparent and abundantly porous; the second retc mucosum-a thick mucous cellular membrane, conspace of two minutes and thirty seconds, and as these contained eighty-two figures, the engine pro-taining in its cells the colouring matter, which, seen duced thirty-three figures every minute, or more than through the cuticle, constitutes the colour of the one figure in every two seconds. On a subsequent skin; and the third, or lowest of the series, the cutis ;-it is from this that the hair springs. Every occasion, it produced forty-four figures per minute; and this rate of computation could be maintained hair originates in a bulb, seated within the skin, for any length of time. which, in one newly pulled, may be seen with the naked eye. It may be proper to add, that Mr. Babbage has lately stated, that he considered the powers of his machine as scarcely at all developed indeed, that the automaton was yet but in its infancy. If such be the childhood of this gigantick engine, what may we not expect from its maturity? There is a general belief that this gentleman has received a large parliamentary grant as a reward for his invention; this is, however, a vulgar errour. He has superintended the construction of the instrument at the expense of the government, but he has not directly or indirectly received the slightest pecuniary compensation for his services. ON THE HUMAN HAIR, Brit. Ency. WITH THE CAUSE OF GRAYNESS IN OLD PERSONS. In its passage through the skin, it pierces the layers in an oblique direction, and thus assists in binding them together. Each hair is composed of two distinct parts, an external tube, and an cuticle in its nature and chymical properties; and internal pith. The former of these resembles the like it is of a white colour, whatever may be the colour of the hair itself. The central portion, or Pith, is that which gives to the hair its peculiar colour. It is composed of extremely delicate vessels, containing a peculiar-coloured fluid. In this respect, it exactly resembles the mode in which the skin itself is coloured. Indeed, it would appear, that the tube of the hair is composed of condensed cuticle; and the pith, a modification of the rete mu cosum. Each hair is accompanied by a nerve and blood Nothing that God has made can be deemed un-vessels, from the latter of which the matter for the worthy of investigation. Every object in nature, growth of new hair is continually deposited. however simple or minute, presents a germ of bound- old persons, when the nervous power begins to less knowledge to the thoughtful mind. Hence so lose its accustomed energy, the colouring matter of common, and apparently insignificant a thing as a the hair ceases to be secreted, and the cellular pith, single hair, when carefully examined, offers a wide which contained it, shrivels up, and is sometimes field of observation to the persevering inquirer. totally absorbed. The tube of the hair is then seen of a transparent whiteness, and in common language a gray head is the result.† The naturalist beholds in it the type of all those species of hair, which, under different and most appropriate modifications, clothe the animal kingdoms. In the insect tribes, he observes it under a thousand beautiful and ever-varying forms, decorating and defending caterpillars, butterflies, and moths. In birds, he observes it to assume the form of feathers, which not only embellish and clothe the animal, but give to the wings and tail a most important part of their locomotive powers. Again in the mammalia, he finds it exhibited in endless but most necessary varieties. None are without it, not even the whales. And in every case the length, quality, and colour, is exactly that which best suits the peculiar wants and instinctive habits of the animal. Fishes and reptiles are totally destitute of hair, and crustaceous animals have it only in particular places, as in the joints of the feet and the margin of the shell, &c. VOL. I.-15 To the chymist, a hair offers an interesting analysis. It has been found by Vauquelin, that black hair is composed: 1, of a considerable quantity of animal matter; 2, a small portion of a white thick oil; 3, another oil, of a greenish colour, in greater quantity than the other; 4, iron-but the form under which it exists is unknown; 5, a few particles of oxyde of manganese; 6, phosphate of lime; 7, carbonate of lime, in very small quantity; 8, silex, or flint, in a large quantity; 9, lastly, a considerable portion of sulphur. To the inquirer in Natural Theology, who looks + Sudden terrour or grief, besides many diseased actions of grief it is supposed that the nerve at the root of the hair suffers the skin, will produce the same effect. In the case of terrour or a paralysis, which stops any further deposition of the colouring matter. HUMAN HAIR, MAGNIFIED 200 DIAMETERS, AS SEEN BY MEANS OF THE MICROSCOPE. A The coloured hair of a person 25 years of age: a the external tube; b the internal coloured pulp. B The white hair from a person 106 years of age: c the external tube, now seen to be transparent; d the remains of the internal coloured pith, separated from the tube, and almost perished; e a smaller hair crossing a larger one, to make their transparency more obvious. Again, he is charmed with noticing the flexibility of hair :-no way impeding the motions of those animals which it clothes-its strength, by which it is cleansed without the slightest fracture-its insensibility to pain; for had it been of a very sensitive nature, it must, from its exposed situation, have been a source of continual pain to the animal.* abroad into the wide and instructive field which comfort and protection. He is particularly struck natural philosophy presents, to find objects demon- with the non-conducting power of hair to heat; for strative of the design and wisdom of the Creator, it is by this that hair is so admirably adapted for the perhaps nothing is better adapted for his laudable winter clothing of animals. Enveloped in hair, the purpose than the study of the organization and struc-heat of the body is effectually preserved from dissiture of this minute portion of the animal frame. He pation-it is shut in with all that certainty which, in admires that infinite power of combination which, the winter season, our furred coats and double blanfrom three primitive colours, has teinted the hairs of kets so comfortably demonstrate. millions of different species of living creatures, each one with a colour distinct and peculiar to itself; the individuality of thousands of genera is thus preserved, which, without it, would have been a scene of monotonous and inextricable confusion. Thus captivated, he looks more closely and from a general survey proceeds to a particular examination; and here new themes for admiration stimulate his industry. He notices the exquisite adaptation of hair to the wants of the creatures-the silky hair of the mole, "the quills upon the fretful porcupine," the mane of the lion, the wool of the merino and the Cachemire sheep-all these he studies, and asks himself, "Whence this interesting variety?" He takes a step further-he observes the difference of hairs on different parts of the same body-as, for instance, those on the mane, fetlocks, and tail of a horse; and he finds in every case that Infinite Wisdom and Infinite Power have been engaged in providing different peculiarities for all those contingencies which would otherwise destroy the happiness of the beings to whom they are now a source of OF THE VARIETIES OF THE HUMAN RACE. The facial line is the profile form of the human head, and in proportion as that comes nearer, or goes farther from, a perpendicular line, that is, in proportion as the forehead projects forward, or slants backward, and the mouth protrudes, so the various tribes are distinguished; that of the negro being most remarkable for this kind of formation, and * Hair is of a vegetative nature, and hence it grows long after been long buried, have been found full of hair, the growth of its death. Instances are on record, in which coffins, after having dead inhabitant. therefore most resembling the construction of the head of an ape. When, however, the frontal bone extends beyond the line of the face, it seems to give an appearance of deformity, and is not often seen, excepting in cases of hydrocephalus, with which children are sometimes afflicted. Europe, the Egyptians, Abyssinians, &c. The facial line of this variety is commonly beyond the perpendicular; that is, the frontal bone extends more prominently than the upper jaw, the cranium is large, face small, oval, and straight; mouth small, and nose rather aquiline, front teeth of both jaws perpendicular, lips rather turned outward, chin full and rounded. Asia. THE MONGOLIAN VARIETY. Those learned anatomists and zootomists who have directed their attention to the science of comparative anatomy, have probably gone too far in imputing a certain construction and form of the head have round faces and heads, their foreheads falling The Calmucks, and most of the Mongolian tribes, to particular tribes of mankind; at least, when they backwards, so as to make an acute angle with the attempt to draw any infallible conclusion from the capacity and form of the cerebrum, respecting the chin, which is short; the nose small and flat; cheek natural talent, sagacity, or intelligence of a multi-bones high; eyes depressed towards the nose; thin, tude of persons; for among those of a single tribe, black, and almost straight eyebrows. This characwe shall find as great dissimilarity of form and size, the Esquimaux, although they live in regions so ter is most conspicuous in China, and extends to as between many of different tribes; and with respect to features, there are some Africans who dif- remote from those of the original tribes in Central fer very little, if any, from Europeans, except in the colour of their skin, and whose facial line will be found as correct and symmetrical as that of the most This class of the human species have the facial regularly formed head according to the rules of line generally more receding at the apex than either sculpture and painting. With regard to intelligence of the former; the forehead is low, narrow, and and talent, all those who have held any commerce slanting; the chin recedes; the eyes are prominent; with the American Indians, most be convinced of all the natives of Africa, south of Egypt, belong to the energy of mind and unsophisticated generosity of temper which these uncultivated people display in all their intercourses of private and political negotiations; in fact, the portrait of Thay Endeneege, one of the chiefs of the most warlike nations, expresses in his countenance the very traits of this disposition. Habit and climate have their influences on man as well as on other animals; and perhaps to these circumstances the varieties in the species are mostly to be attributed; for there is scarcely a greater difference between a mountaineer of North Britain, and a Calmuck Tartar, than there is between that mountaineer and a native of London. However, to give a correct idea of the physiological distinction that is commonly made between the European and the Negro, and other tribes, the following heads are subjoined; that of the Negro being in the extreme of the variation, that of the European in the form of the best models. That these variations of form in the features and construction of the human head should be a criterion on which to found any speculative theory respecting the mental qualifications, is a subject rather of a hypothetical nature, and to enter into which would require much actual experiment, if we would be quite correct and certain of the data from which our deductions should be made. Instances occur of great talent and sublime imagination, where apparent deformity has existed; and symmetry has not always been attended by qualities of high mental endowments. What is meant by the facial line, as a distinction, will be best understood by the following outlines of the heads of the different portraits. But it must never be forgotten, that the shape of the head, and, consequently, the angle of the facial line, by many uncivilized people, are artificially produced, a fact to which neither sufficient attention has been paid, nor sufficient weight allowed. this tribe. THE ETHIOPIAN VARIETY. THE AMERICAN VARIETY. The facial line of the native Americans differs very little from that of the Mongolian tribes, the forehead being low, the eyes deep, and face broad, yet not quite so much flattened; their features are larger, and more distinct and projecting: from this class we must exclude the Esquimaux and the people of Nootka sound, who differ very materially. THE MALAY VARIETY. This class is distinguished by a large mouth, narrow head, the bones of the face large and prominent, nose full and broad towards the apex; the facial line, is for the most part, more inclined than in the other varieties, and approximating, in some instances, to that of an ape: no variety, however, differs more than this in character and appearance. b PROFILE OF THE EUROPEAN. The distinction in this profile is the perpendicular |