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Fig. 3.

THE COMB-CUTTING ENGINE.

from time to time, until at length a complete junction

takes place. The teetn of combs were originally cut by means

The engine represented in the engraving is copied of a double saw, one blade of which was twice the from the Transactions of the Society of Aris, vol. 47. length of the other; the teeth were cut as follows:

The cutters are seen at a A, fig. 3; they let a, fig. 1, represent the piece of horn or wood, out

are arranged in this manner :-a a are of which the comb is to be cut; it is of the exact size the edges of the chisels set at an angle 6 of the comb.

B is the saw with its two unequal by c, which is called the filling-up piece: blades; the first cut of this saw has already made ő is a smaller chisel which cuts away

the point of the tooth from the shell, to
Fig. 14

which it would otherwise be attached;
but this small chisel only effects this
operation on one of the combs: the opposite teeth are
cut away by the bent ends d d of the longer chisels,
which at each blow half separate two teeth.

a

B

Fig. 4.

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two nicks in the material, that by the longer blade to the full depth of the tooth, and that by the shorter to half the depth; the longer blade is now placed in the shallow nick, which it deepens to its full

B extent, while a third nick is made by the shorter blade : in this manner the whole of the teeth were gradually marked out, and were afterwards finished by means of files. The next improvement was the employment of circular saws of different diameters, instead of the two-bladed straight saw.

The manner in which combs are cut at present is an apt illustration of the advantage derived to manu. The shell is firmly fixed beneath the cutter A, and factures and the arts by the inventions of ingenious the engine acts in the following manner:-B is a men, directed frequently by accident. About twenty strong bar firmly jointed behind to the framework; it years ago, the principal house in London for the sale is kept steady by the loop c, and is moved downwards of combs had received from abroad some patterns of by means of the crank in front, carrying along with ornaments, like the spikes and balls of coronets, to it its cutters upon the shell. This crank is moved be attached to tortoise-shell combs. They gave the by the handle and winch E; and is so fixed that it order to execute these to an ingenious artist of the brings down the cutter upon the shell at that part of name of Ricketts, who contrived a punch, by the the revolution of the winch, when the wheel with a few successive pressure of which, on a thin piece of warm teeth which is fitted to its axis, is clear of the teeth tortoise-shell, he cut out the pattern piece by piece; of the larger wheel. As soon as the tooth is cut, the on disengaging the pattern from the other part, he crank in its revolution raises the lever and cutter, observed to himself, “ Here are two combs cut out and the teeth on the small wheel entering those of the of the material for only one." He improved on this larger, move the large wheel a part of a revolution. hint, and constructed a machine in which he em- This large wheel is fixed to a screw which is attached ployed a cutter like a chisel, which, descending upon to a sliding table, on which the tortoise-shell is placed; the shell, cut one side of a tooth at a time, and then, the screw is consequently turned a part of a revoluby shifting the bed on which the shell was laid, and tion, and the shell and table thrust forward propormoving it forward a short distance, the other of the tionately. The smaller wheel becomes again distooth was cut: the result of this operation may be engaged from the larger, the crank again brings down seen in fig. 2, which re

the cutter on the shell, and another tooth is cut, and presents a piece of shell

Fig. 2.

this alternate action takes place until the two combs very little larger than

are cut out. Another piece of shell is supplied, and necessary for one comb,

the movement of the handle of the winch being rebut which, by this

versed, the shell and the table nove back to their means, is made to pro

former position, and two more combs are separated. duce two.

If combs with finer teeth are required, the large When the knowledge of this engine degan to wheel is changed for another with more teeth on its spread abroad, various contrivances were resorted to circumference, and the cutters are also set at an to guide the direction of the cutter, so as to cause it acuter angle. to descend obliquely and at regular intervals; but this oblique action was next avoided by the employment LIBERTY is to the collective body, what health is to every of two cutters, or chisels, placed at an angle with each other, by means of which a perfect tooth is cut by man; without liberty, no happiness can be enjoyed by

individual body. Without health, no pleasure can be tasted at one blow. The scales of tortoise-shell being much

society.-- BOLINGBROKE. thinner on one edge than the other, were not so well adapted for this invention as horn, the thin edge not It is impossible to make people understand their ignorance; being thick enough for the back of the comb: but for it requires knowledge to perceive it; and therefore be

-BISHOP TAYLOR. this can be remedied by soldering another piece of that can perceive it hată it not. shell upon the thin edge; it is effected in this manner. The two surfaces to be united are nicely rasped

LONDON: and smoothed, placed between two thin boards, and JOHN WILLIAM PARKER, WESI STRAND. submitted to the action of a screw-press.

PUBLISHED IN WEEKLY NUMBERS PRICE ONE PENNY, AND IN MONTHLY Pasm is put for some hours in boiling water and tightened

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NEWCASTLE-UPON-TYNE, AND THE GREAT NORTHERN COAL-FIELD. II.

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TRAL

GREY-STREET-STATUE OF EARL GREY-THE CEN

Earl Grey in his parliamentary robes. The statue Is EXCHANGE-MEAT, POULTRY, AND VEGE

fourteen feet high, and is an excellent likeness. The TABLE MARKETS-ROYAL ARCADE-TYNE BRIDGE.

total height of the column is 135 feet; a circular We come now to the examination of the new buildings staircase within leads to a balcony at the base of the erected by Mr. Grainger, a gentleman of whom New- statue, from whence a fine panoramic view of the castle is justly proud. Emerging from a compara- surrounding country may be obtained. This column tively humble station, he displayed at an early age is so placed as to form the termination of Greysuch extraordinary talent as an architect, that he was street, called after the noble earl; and of Graingerat once employed to erect every public building re- street, which derives its name from the public-spirited quired in the town; and the singular beauty of his architect. The best view of it, however, is from structures created a desire for fresh buildings, while Eldon-square, so called in honour of Lord Eldon, his integrity won him the confidence of capitalists late Lord Chancellor of England, who was a native able to bear the expense of extensive speculations. of Newcastle.

Grey-street is without a rival in the world as a street The most striking view of Grey-street is from the built merely for business, and resembles rather a street top of Dean-street; for though the Grey-column is of palaces than houses. It surpasses Regent-street, hid by the windings of the street, the cupolas of the London, in the richness and variety of its architecture, Central Exchange are seen at the termination of the and in the harmonious arrangement of its parts, and vista, and produce a very striking effect by the gorit has the decided advantage of being all built of solid geous, bronze plumes sculptured on their summits. stone, instead of brick faced with stucco. It was The Central Exchange was erected by Mr. Grainger erected in the short space of three years, though its for a Corn-market, and offered to the corporation as elaborate workmanship would seem to have required a free gift. Externally this splendid building disthe labour of a century. The buildings form groups, plays a rich Corinthian front, slightly varied by the each of which seems to be one great public edifice, introduction of the other orders, without, however, worthy to have been raised by some powerful monarch. weakening the unity of the design. But it is scarcely The central group on the west side, occupied by the possible to describe the sensations produced by the Northumberland District-Bank, and the Branch-Bank interior; it presents a semicircle of 150 feet in of England, has all the splendour of a palace. Al- diameter, with an additional oblong area of twenty though they are elaborately finished, there is nothing feet wide adjoining the diameter. The principal tawdry or meretricious in these edifices, for the parts entrance opens into the semicircle, and is surrounded harmonize with each other, and all the parts are so by twelve massive and lofty pillars of the Ionic order, exquisitely proportioned, that we feel while looking at with fancy embellishments. The light of this gigantic each building, “here is nothing to be added and edifice is obtained through rather more than ten nothing to be taken away, without injury to the thousand square feet of glass in the sides of the roof striking effect of the whole.” At the point of entrance and the crown of the dome. The roof is constructed from the north to Grey-street and Grainger-street, a on a novel principle, somewhat similar to that used column is erected surmounted by a colossal statue of ! in the finest specimens of ecclesiastical architecture, VOL. XIII.

414

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and has a very striking effect when viewed from for one evening during the recent visit of the British below. During the recent meeting of the British Association to Newcastle, and the scene which it dis Association in Newcastle, the Central Exchange was played resembled enchantment rather than the work used for the general meetings of the Association, and of human hands. furnished accommodation for nearly six thousand The Royal Arcade ranks next to the markets in persons. On this occasion its acoustic powers were beauty and convenience. Its front is 94 feet in severely tested, and it was found to be one of the length and 75 feet in height; the entrance is adorned best rooms for hearing in, notwithstanding its vast with two massive pillars of Doric architecture, and size, which the Association has found in any place it the entablature is surmounted by six Corinthian has yet visited. Under a colonnade of four Ionic fluted columns, over which is a richly carved frieze. columns inside of the Exchange, and by a double From the front the arcade extends eastwards, and flight of stone steps from Market-street, are entrances consists of three stories, the basement Doric, and to the exhibition-room and other chambers of the the upper Corinthian, forming an extensive range of North of England Society for the Promotion of the sixteen shops and offices, with cellars and shops Fine Arts. The exhibition of sculptures and paintings below, occupying one entire side of Manor-street. this year, though inferior in quantity to that of the The length of the building is 250 feet, the breadth is National Gallery, was fully equal to it in quality, and 20 feet, and the roof, which is 35 feet in height, con it deserves to be remarked that most of the best tains eight conical lanterns, which amply illuminate specimens were the work of native artists. In one the building In this edifice are the Post Office, the of these apartments a room was opened for the exhi- Excise Office, and several other public offices, all of bition of specimens of British art and manufactures which are very spacious and convenient. during the recent meeting of the British Association, Tyne Bridge is an edifice of great strength and and here also the talents of the Newcastle people some beauty; near it is the Close, where anciently were conspicuous, especially in the models for steam- the principal inhabitants were accustomed to reside, machinery, and for the construction of bridges on before Mr. Grainger erected his “city of palaces” in railways.

the Upper Town. Most of these houses are now The meat, poultry, vegetable, and butter markets, occupied as stores or manufactories are all under one roof, occupying a space of about two acres, having Grainger-street to the east, Claytonstreet to the west, Nelson-street to the north, and Nun-street to the south. These markets occupy the

ON THE STETHOSCOPE, OR CHEST.

EXPLORER. site of a spot called the Nuns'-field, which once belonged to the nunnery of St. Bartholomew, and joined One of the most remarkable instances of the applithe grounds of the Franciscans, or Grey-friars. This cation of physical science to the alleviation of human circumstance did not escape the notice of the local suffering, is presented by the little instrument known poets who abound in Newcastle, and it was com- under the name of the Stethoscope. The principle on memorated in a song. We may add that there has which this instrument acts, and the service which it been scarcely any change made in Newcastle within is calculated to render to the medical practitioner, the last century, which has not been commemorated admit of being popularly explained, without entering in a local ballad.

upon the refined difficulties of the medical treatment The butcher market consists of four spacious of diseases: we propose, therefore, to give this explaavenues, each 338 feet in length, 20 feet in breadth, nation. and 27 feet in height. The light descends in the Almost every kind of motion, whether of a solid, eastern avenue from fifty sky-lights, through apertures a liquid, or an aëriform body, is calculated to produce in the coffer ceiling, with a most pleasing effect; there a sound, more or less audible to the ear: the blast are also the extraordinary number of 360 glazed sashes of air which we blow into a flute, and the rush of to open and shut as the weather may require. These wind through the key-hole of a dvor, are, alike, four principal avenues are crossed by four lofty ar- instances of the production of sound by the motion cades, each twelve feet wide. In the evening the of air: the mighty crash produced by a cataract, or whole is lighted with gas, and has a most brilliant the rippling noise of a flowing brook, show us that effect.

the motion of a liquid is a source of sound : while The vegetable market consists of one spacious and the great majority of our musical instruments, and of splendid hall, 318 feet in length, and 57 in width, the sounds which meet the ear in every-day life, within the fronts of the fruit and vegetable shops, afford us proof of the effect produced by the vibra. being of greater dimensions than the venerable hall tion, the friction, or the progressive movement, of of Westminster. The roof, upwards of forty feet in solid bodies. height, is framed of timber-work in the cathedral Now, if we consider the structure of the human style; it is supported by thirty cast-iron pillars, from frame, we become conscious that there are incessant each of which, at the height of twenty-six feet, is movements going on in the interior of the body, the suspended a large gas-lamp. The roof over the cessation of which can only occur when death stops central space is enclosed by a glazed lantern, ex- the living machine. The flow of blood to and from tending the whole length of the hall, while the sides the heart, the entrance and exit of air in the process are lighted by 104 windows. In the centre of the of respiration, the forcible passage of air in the promarket are two magnificent fountains, similar to the cess of speaking or singing, all produce sounds difcelebrated fountain in the Borghese Palace at Rome; fering in intensity and character according to cir. the basins are each capable of containing three thou- cumstances. Again ; if the bony or fleshy parts of sand gallons of water, and they throw up a jet of the body be struck, the parts are set into a vibratory twelve feet in height; the water falls into splendid state, from which results a dull imperfect sound; vases of six feet in diameter, beautifully sculptured and this sound is more or less modified by the nature with foliage and tracery, over whose circumference and contents of the cavities which are encompassed the water falls in a graceful shower into the large by the bony or fleshy portions. basins below, This market, which is without a A consideration of these circumstances gradually parallel in the world, was fitted up as a promenade led medical men to the inouiry how far the sounds

emitted by the human body would afford indication

I happened, (says he,) to recollect a simple and wellof the existence of disease within the system. The known fact in acoustics, and fancied that it might be turned lungs, for instance, are suspended in the cavity of the to some use on the present occasion. The fact I allude to chest, and both within and without the lungs air is, the great distinctness with which we hear the scratch of exists, which air modifies the sounds produced by the

a pin at one end of a piece of wood, on applying our ear at natural or the artificial action of the lungs. Now, of paper into a cylinder, and applied one end of it to my

the other. Immediately on this suggestion, I rolled a quire if through the influence of disease, the solid sub patient's chest, and the other to my ear, and was not a lizle stance of the lungs become either smaller or larger in surprised and pleased, to find that I could thereby perceive bulk than the natural size, the quantity of air to the action of the heart, in a manner much more clear and fill the vacant spaces must be changed, and the reso- distinct than I had ever been able to do by the immediate nant or echoing effect of sound against the sides of application of the ear.” the cavity of the chest, more or less interfered with. Here at once was opened to M. Laennec a new If, therefore, in a state of health, a particular sound field of investigation, from which he obtained most be emitted from the chest, and if, during the existence fruitful results. From his simple quire of paper he of asthma, a different sound be heard, the physician proceeded to other materials which he thought might would take that difference of sound as a symbol of be better fitted for the object in view. In this inquiry the existence of asthma: and so with any other he was led to the adoption of an important principle disease.

in the science of acoustics, namely, that sonorous Acting on these principles, Auenbrugger, a physi-vibrations are communicated from one body to cian of Vienna, suggested, in 1761, the mode of per- | another more perfectly, when the conducting body cussion, as a means of determining the healthy or resembles in density the body which is vibrating; unhealthy state of the system. The chest, and other that is, that a column of air is best fitted for conhollow parts of the body, were struck briskly, but ducting vibrations excited in air, but that a solid not forcibly, with the ends of the fingers, and the ear conductor is more appropriate when the vibratory was applied so as to listen to the sounds resulting body is a solid or a liquid. Now, Laennec considered from the blows; and an earnest and unremitting that the sounds emanating from the chest, arise from attention to the sounds thus elicited, enabled phy- the motion of air to and from and within the lungs; sicians to discriminate between that character of whereas, the sounds emitted from the heart are sounds which indicated a sound state of health, and caused by the motions of a liquid; that is, the blood. those which appertained to disease; and still further, He therefore conceived that a column of air would between those belonging to one disease, and to a be the best conductor when the motions of the lungs different disease. Before we doubt the probability of were to be investigated, but that a solid cylinder of detecting difference of sound in this way, we must wood would be a better form when the motions of remember how very similar are the means by which the heart were to be observed. He procured cylinders artisans frequently hear the state of their work : a and tubes of various kinds, and found that a convebricklayer, by striking a few smart blows on a wall, nient length for this instrument was about ten or can frequently determine the thickness and nature of twelve inches, and about an inch and a half in it, by the sound which results from the blow. A diameter. This he formed of walnut, cedar, and carpenter can, by similar means, determine the posi- other kinds of wood, in order to determine which is tion of joists, &c., under a boarded floor. These best fitted for the purpose. facts prepare us to admit another, that percussion on The movement of the air in and round the lungs the chest has been, and still is, resorted to as a means during respiration, differs from that occasioned by of detecting the existence of disease in the lungs, the voice, inasmuch as the latter is confined prinheart, and adjacent parts.

cipally to two tubes or canals proceeding from the cases the chest itself was struck; in lungs to the throat; whereas, during respiration, the others, a layer of cloth was placed between the fingers whole cellular substance of the lungs furnishes and the chest; and M. Piorry, a French physician, series of little canals for the passage of air. Laennec suggested the application of a thin solid plate between conceived, therefore, that to obtain indications of the the fingers and the chest, as being advantageous existence of disease in the lungs, it would be desirable under some circumstances. But it will be observed, to use a tube, one end of which was spread out like that in all these cases, the sound elicited is an arti- the mouth of a trumpet, by which the action of a ficial and unnatural one, not resulting from the larger space might be tested; but for those parts of regular movements in the system, but from a disturb the contents of the chest connected with the direct ance caused from without. It therefore occurred to production of voice, he found a hollow cylinder, physicians, that by placing the ear close to the chest, equal in diameter through its whole length, to be the the natural actions of the system might be heard most favourable form. going forward, and that in a state of disease these The instrument thus formed he termed the Stethosounds might be different from those heard in a state scope, from two Greek words signifying a chestof health. This plan has been pursued with con- explorer,-a name significant of its employment. siderable success, as a means of obtaining symptoms The three forms of the instrument are conveniently which may guide the physician in his mode of treat- combined in one, by a little judicious arrangement. ment.

A cylinder nearly a foot long, and an inch and a But an improvement of an important kind was half in diameter, is employed as a Stethoscope for made in this mode of operation by M. Laennec, a the heart : a small tube bored through the middle of French physician of great eminence. This gentleman this cylinder, serves as the Stethoscope for the organs was born in Bretagne, in 1781, and while yet a young of voice; and by unscrewing part of the length of man, greatly distinguished himself by his skill in the cylinder, and fixing on a trumpet-shaped piece, auscultation, that is, hearing the sounds emitted by the instrument assumes that form most advantageous the chest, &c., during the natural actions. In 1816, for the exploration of the respiratory organs. he was called to attend a patient who had an affection One of the most difficult parts of Laennec's inof the heart, and being unable to obtain the requisite quiry, was, to find proper language in which to symptoms by the application of his ear, he devised a describe the various sounds which the actions of new mode of proceeding.

the body emitted. He published a work expressly

In some

a

relating to auscultation by means of the Stethoscope ; | find an explanation of the movements of the pithand when detailing the symptoms which indicated balls. The redundant electricity accumulated on the disease, he had to convey a correct idea of the sort of inside of the glass, has a tendency to escape to the sound belonging to each disease. Some of his com outside ; but glass being a non-conductor, a commuparisons are remarkable : one sound is compared to nication is more readily effected by the pith-balls the rush of wind through a small orifice : another to than it would be if the glass were left to itself. The the flapping of a valve: another to the creaking of balls, therefore, attracted by the electricity on the the leather of a new saddle: a fourth, to the sound inside of the glass, leap from the table towards it, produced by stroking the head of a cat while the and having received a charge of positive electricity, animal is purring. There is nothing absurd or trifling are instantly repelled by the glass and attracted by in such comparisons, since it is as impossibe to find the table, to which they return, and after delivering appropriate and expressive names for all the varieties what they have received, leap again to the glass for a of sound, as for all the tints of colour: in order, further supply. These alternate movements continue therefore, to convey to others a precise idea of the until the force of gravity acting on the balls, and the nature of a sound, it is necessary to adopt such a attractive influence of the glass, are exactly balanced. standard of comparison as is familiar to most persons. Whilst the pith-balls are engaged in carrying

In the application of the Stethoscope, the ear is positive electricity from the inside of the glass, it is applied closely to one end, whilst the other end is necessary that negative electricity should in the same placed against various parts of the chest, according proportion make its escape from the outside; a proto the spot which it is wished to explore. In some cess which is greatly accelerated by passing the hand cases a tube of caoutchouc, or Indian rubber, has over it. Hence it happens that the balls, after having been employed instead of wood; but the impos- been some time at rest, may in this way be made to sibility of rendering the internal surface of such a resume their movements. tube perfectly smooth and cylindrical, detracts from Another experiment, furnishing an example of its usefulness; for whenever sounds have to be con- electrical repulsion, is effected by means of what is veyed through a tube, it is of much importance that called an electrical head of hair ; consisting of a the sides of the tube should be free from any pro- block of hard wood, carved and painted to represent tuberances or roughness of surface.

a human head, and covered with long hair, the finer the better. A piece of wood, or stout brass wire,

projects from the lower part of the head, by which it ELECTRICITY.

is fixed to the conductor. On putting the machine No. V.

in motion, the electricity excited by it escapes at the

points of the hair, which separate and stand erect, ELECTRICAL EXPERIMENTS.

presenting a most grotesque appearance, and which The following, notwithstanding its apparent simpli- is occasioned by each hair being similarly electrified.; city, is as good an experiment as we can select for illustrating electrical attraction and repulsion.

Having provided a glass vessel of the form represented in the annexed figure, or a large tumbler will

do equally well, let it be wiped
clean and perfectly dry, and
by means of a pointed wire
attached to the positive con-
ductor of the electrical machine,
the inside of the glass must be
charged with electricity. If it
then be placed on a table, and Το Ω γοΙοττΙΣ
made to cover a dozen or two
of pith-balls, the latter will
immediately begin to leap from

the table to the top and sides These examples, all tending to illustrate the same of the glass, and back again, and this they will con- principle, may be greatly multiplied; and although tinue to do for several minutes. When the motions the apparatus partakes in some respects of the chaof the balls have ceased, they will almost always be racter of philosophical toys, yet it is not on that renewed on passing the hand gently over the outside account to be despised. Of this class is the electrical of the glass.

bells, which are so arranged that, by the alternate With so great a number of balls as we have men- attractions and repulsions of small brass clappers tioned, this experiment is, perhaps, more amusing placed outside them, a constant peal is kept up. The than instructive; but when only about half a dozen arrangement is as follows; (see fig.) a is a brass are used, and those of different colours or sizes, if hook fixed to a piece of wire, the length of which we watch attentively their movements, we shall have must be determined by the size of the bells, and it no difficulty in understanding the cause.

may either be straight or curved, but the latter form On presenting the inside of the glass vessel to the is the best. 666 are three bells, the outside ones pointed wire, as just described, its surface becomes suspended by brass chains, but that in the centre by coated with positive electricity, and at the same time, silk cord, as are also the clappers cc. The centre and exactly to the same degree of intensity, the out- bell is made to communicate with the table or floor side of the glass will be negatively electrified. The by a piece of chain c. instant the glass is placed on the table, the pith-balls The bells being attached to the positive conductor and that part of the surface of the table directly by the hook a, on turning the machine the electricity underneath it, are similarly affected. We have before endeavours to make its escape down the chains by stated as a first principle in this branch of science, which the two outside bells are suspended, and which that bodies similarly electrified repel, those dissimi- are, of course, positively electrified ; that in the larly electrified attract each other. Here, then, we centre, by its communication with the earth, being in

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