single pound on the divided circle of the next train. Notwithstanding the skill and contrivance bestowed upon instruments of a nature similar to that we have just described, their power is necessarily but very limited, and they bear no comparison either in ingenuity or magnitude to the grand design conceived, and nearly executed, by Mr. Babbage. Their very highest functions were but to perform the operations of common arithmetick; Mr. Babbage's engine, it is true, can perform these operations, it can also extract the roots of numbers, and approximate to the roots of equations, and even to their impossible roots; but this is not its object. Its function in contradistinction to that of all other contrivances for calculating, is to imbody in machinery the method of differences, which has never before been done; and the effects which it is capable of producing, and the works which, in the course of a few years, we expect to see it execute, will place it at an infinite distance from all other efforts of mechanical genius. Great as the power of mechanism is known to he, yet we venture to say, that many of the most intelligent of our readers will scarcely admit it to be possible, that astronomical and navigation tables can be accurately computed by machinery; that the machine can itself

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 de scribed 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 in-correct the errours which it may comnit; and that tended 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 e.tended.

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.

66

the results, when absolutely free from errour, can be printed off without the aid of human hands, or the operation of human intelligence. "All this, however," says Sir David Brewster, in his entertaining Letters on Natural Magic, Mr. Babbage's machine can do; and, as I have had the advantage of seeing it actually calculate, and of studying its construction with Mr. Babbage himself, I am able to make this statement on personal observation." It consists essentially of two parts, a calculating, and a printing part, both of which are necessary to the fulfilment of the inventor's views, for the whole advantage would be lost if the computations made by the machine were copied by human hands and transferred to types by the common process. The greater part of the calculating machinery, of which the drawings alone cover upwards of 400 square feet of surface, is already constructed, and exhibits workmanship of such extraordinary skill and beauty, that nothing approaching to it has hitherto been witnessed. In the printing part, less progress has been made in the actual execution, in consequence of the difficulty of its contrivance, not for transferring the computations from the calculating part to the copper, or other plate destined to receive them, but for giving to the plate itself that number and variety of movements which the forins adopted in printed tables may call for in practice.

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 acrains 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 enor course. 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 theber 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, besides logarithmick tables, Mr. Babbage's machine will calculate tables of the powers and products of numbers, and all astronomical tables for determining the positions of the sun, moon, and planets; and the same mechanical principles have enabled him to integrate innumerable equations of finite differences, that is, when the equation of differences is given, he can, by setting an engine, produce at the end of a given time, any distant term which may be required, or any succession of terms commencing at a distant point.

takes the trouble to carry on the table a few terins further. Now, when once this is admitted as a known fact, it is quite clear that, provided the first term (1) of the table, the first term (3) of the firstdifferences, and the first term (2) of the second or constant difference, are originally given, we can continue the table to any extent, merely by simple addition: for the series of first-differences may be formed by repeatedly adding the constant difference 2 to (3) the first number in column B, and we then necessarily have the series of odd numbers, 3, 5, 7, &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 successive addition and substraction of numbers befitting each table, is a general principle which can be demonstrated to those only who are well acquainted 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.

C.
Second
Difference.

2

Α.

Terms of Table of
the Table. Squares.

B. First Difference.

1

1

3

2

4

5

3

9

2

7

4

16

2

9

5

divisions to which the hand points. Let it be sup-
posed that two of the clocks, for the sake of distinc-
tion called B and C, have some mechanism by which
the clock C advances the hand of the clock B one
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,

for example, appearing in figures before the person employed in copying. The following table was calculated by the engine referred to :—

1373

41

131

383

797

43

151

421

853

1447

47

173

461

911

1523

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. While the machine was occupied in calculating beautiful and economical piece of mechanical conThe anatomist sees in the structure of a hair, a this table, a friend of the inventor undertook to write down the numbers as they appeared. In consequence trivance. Taking the human hair for example, he of the copyist writing quickly, he rather more than observes, first, that as an appendage to the skin, it 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 rete space of two minutes and thirty seconds, and as mucosum-a thick mucous cellular membrane, conthese 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 occasion, it produced forty-four figures per minute; and this rate of computation could be maintained for any length of time.

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

WITH THE CAUSE OF GRAYNESS IN OLD PERSONS.

cutis;-it is from this that the hair springs. Every hair originates in a bulb, seated within the skin, which, in one newly pulled, may be seen with the naked eye. In its passage through the skin, it pierces the layers in an o. que 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 Fith, 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. In however simple or minute, presents a germ of bound less knowledge to the thoughtful mind. Hence so common, and apparently insignificant a thing as a single hair, when carefully examined, offers a wide field of observation to the persevering inquirer.

old persons, when the nervous power begins to lose its accustomed energy, the colouring matter of the hair ceases to be secreted, and the cellular pith, which contained it, shrivels up, and is sometimes totally absorbed. The tube of the hair is then seen of a transparent whiteness, and in common language

The naturalist beholds in it the type of all those species of hair, which, under different and most ap-a gray head is the result.† propriate modifications, clothe the animal kingdoms. To the chymist, a hair offers an interesting analyIn the insect tribes, he observes it under a thousand sis. It has been found by Vauquelin, that black 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.

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; the internal coloured pulp. B The white hair from a person 103 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.

abroad into the wide and instructive field which natural philosophy presents, to find objects demonstrative of the design and wisdom of the Creator, perhaps nothing is better adapted for his laudable purpose than the study of the organization and structure of this minute portion of the animal frame. He admires that infinite power of combination which, from three primitive colours, has teinted the hairs of 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

comfort and protection. He is particularly struck with the non-conducting power of hair to heat; for it is by this that hair is so admirably adapted for the winter clothing of animals. Enveloped in hair, the heat of the body is effectually preserved from dissipation-it is shut in with all that certainty which, in the winter season, our furred coats and double blankets so comfortably demonstrate.

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.*

OF THE VARIETIES OF THE HUMAN RACE.

ON THE FACIAL LINE.

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 death. Instances are on record, in which coffins, after having been long buried, have been found full of hair, the growth of its dead inhabitant.