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ROOKE'S IMPROVEMENTS IN THE JACQUARD LOOM.

portions of the pattern itself. In patterns of no uncommon extent, the number of cards required is 1700 or 1800, nearly half of which are repetitions of a very few being wanted for the plain work alone.

In vol. xl. of the Society's Transactions is a description of the old loom, with an improved draw-boy by which the figure or pattern was determined. In vol. xlvii. will be found Mr. Hughes's improvement on the Jacquard loom, by which one set of cards is made to hold two patterns; and in vol. xlviii. is Mr. Jennings's improvement of the Jacquard machine, and also a simplified machine by Mr. Dean.

Mr. Rooke's improvement relieves the band from all the repeating cards which form the ground, and causes their work to be done from a second treadle; thus easing the weaver by the more equal use of his legs on two treadles, and saving a considerable expense and bulk of cards.

For this purpose Mr. Rooke constructs a very small Jacquard machine, and places it at the back of the larger one, and at right angles to it, and this is wor7ed by a treadle at the other foot. With this small machine he uses a little band, containing no more cards than there are variations in those repetitions of which the great band of cards is thus relieved.

Fig. 1 is a view of the small machine taken from the back of the loom; consequently, if the whole loom was shown, the larger machine would be seen behind this.

aa is the compass-board, bb the usual lifting cords from the large machine xx. Mr. Rooke's additional lifting or binding-cords proceed in twenty-four pairs from the large machine to the twenty-four shafts dd, and cc are the lifting-cords from his small machine which proceed in eight pairs to the same twenty-four shafts: these being sixteen in number, form eight pairs; each pair is divided into three; these three join three of the cords xxx, and go to the ends of three shafts dd, as shown in fig. 8: so three are lifted together by the small machine, there being twenty-four shafts and only eight changes these threes are used for a satin ground: when other grounds are to be formed, the shafts are arranged so that two or only one may be lifted by each pair of cords from the small machine, the small band in that case containing a suitable increase of cards: the holes in these cards are always in pairs, in order the better to lift the shafts at each end. e is the revolving bar, f the band of eight cards upon it, corresponding with the eight pairs of lifting cords: they are kept conveniently extended by a light rod gg, so as to revolve very correctly with the bar e.

Fig. 2 is a larger view of the small machine, and fig. 3 a side view, h is the lever

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by which it is moved: if this were long
enough to pass the large machine, the treadle:
would not give it sufficient motion; therefore
it is met by another lever i, which receives:
motion from the treadle behind the weaver.
The lever h turns the pulley j; this by a cord
k raises up the lifting-frame 1, shown only by
dotted lines in fig. 3. When this has taken
up the proper hooks, the string m becomes
tight enough to pull in the top of the batten
n; this protrudes the batten-frame
00, which
hangs on centres pp, and also causes the bar
e to revolve by the hook q retaining one cor-
ner of the bar whilst the rest is being carried
out, and thus causes a quarter turn: a spring
attached to the frame o pulls it back again
quite close as soon as the treadle is suffered
to rise, and presses the next card against the
needles, the blanks pushing in those needles
whose hooks are not to be raised. These
machines are made with single, double, or
quadruple rows of lifting-hooks according to
their work. Fig. 1 has but sixteen hooks,
and all in one row; fig. 2 has twenty-six in
a row; and fig. 3 shows four such rows, form
ing what is called a short one-hundred
machine.

In the machines formerly described, each of the four sides of the revolving-bars was bored with as many holes as there were needles, and in as many rows as there were rows of hooks. Mr. Rooke, instead of forming each row of distinct holes, cuts a continued groove in the prism, of the same depth as the holes, whereby he obtains increased facility in adjusting the pattern-card to the ends of the needles, and spares the care that otherwise would be required to keep the holes strictly equidistant.

In fig. 1, the bar e has but one groove on each side; in fig. 2, two grooves are shown; whilst to make it suit fig. 3, four such grooves would be required. The liftingframe slides as usual in grooves within the outer frame; in fig. 3, the bars are seen by dotted lines just under the hooks they have to lift. In fig. 4, four hooks are shown, and only two of the needles; rr are the springs that protrude the ends of the needles towards the bar e; fig. 5 is a top view of one needle, s is the bend against which the spring r acts; a small wire passes through the bend t, which prevents the needles from ever being pushed too far by the springs r, and confines them to the bar u. vv, figs. 1, 2, and 3, are screws to adjust the revolving-bar e correctly to the needles; nuts gg are also placed on them, through which the rod g passes to extend the band of cards; these enable the rod to be adjusted to the exact height. The end adjustment of the revolving-bar e is given by the screw-centres pp. The lower hook w is merely to cause a return of the band of cards, and thus undo the work, should any accident

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ON TUNING-MATHEMATICAL DIVISION OF THE SCALE.

require it. To effect this, a string from the tail of hook q lifts it out of contact with the revolving-bar, and at the same time brings the hook w in contact with it by means of the wire qw, which connects the two hooks: this causes the bar to revolve in the contrary direction, merely by the same action of the treadle as would be required for going on with the work, and thus, by reversing the motion of the cards, enables the workman to unravel till he arrives at the part where any error has been committed.

This monture, as before stated, contains twenty-four shafts dd, connected in threes to the small machine by eight pairs of binding or lifting-cords cc. These twenty-four shafts have all the warp attached to them, and are also all connected to the larger machine, not in sets, but singly by twenty-four pairs of binding-cords xxx: thus either machine will lift the shafts, so that there are three ways by which the warp can be raised; first, by the shafts and small machine, in eight portions; secondly, by the shafts and large machine, in twenty-four portions; and, lastly, by the large machine, in the usual variable portions, without the shafts.

The holes in the cards, and the hooks by which the large machine lifts the shafts, are purposely placed outside the other sets, the better to distribute them in pairs, and also to keep the weight equal on the lifting-frame 1.

Fig. 6 is a side view with respect to the loom, and an end view of the compass-board: it shows the twenty-four pairs of lifting-cords xx divided, one half to the right and the other to the left, so as to be lifted by hooks at each end of the frame b. ce are the liftingcords from the small machine: here one half is hid behind the other, the hidden part proceeding to the other end of the compass-board (as shown in fig. 1); the dots at the lower c show where they divide into three-of course, the higher they are divided the less will be the divergence of the cords-they then are joined to the cords xx, just above the compass-board a, as seen in fig. 8. dd shows the ends of the twenty-four shafts, and yy the warp. b shows the usual lifting-cords from the Jacquard machine placed between the additional ones. Fig. 7 shows two lifting. cords a and c proceeding from the two machines towards the compass-board, just above which they join, and then pass through to the end of a shaft d. bbb show three of the usual lifting-strings, one up, the others down; they have loops bb through which the shaft passes, so that they can go up singly like the one shown raised, but when either machine lifts a shaft it takes all up together.

In this machine, when a figure of one colour is worked on a ground of one other colour, the two treadles are alternately used; if the figure has two colours, the treadle of

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These multipliers are not arbitrary numbers, but as the second stage brings us beyond the first octave, we must double it to bring it within the octave; and as the fourth stage brings us beyond the second octave, it must be twice doubled (or quadrupled), and so on of the rest.

A piano-forte tuned according to this scale would, I think, have a very pleasing. effect; but, independent of the impossi bility of tuning to that exactness, pianoforte-makers, instead of doubling the length of string to produce the sound of

WIDENING OF BLACKFRIARS' BRIDGE.

the octave below, must necessarily use a thicker wire, or we should have pianofortes as large as houses.

The following is Earl Stanhope's scale:

C-C, perfect octave.
C-G, perfect fifth.
C-E, perfect third.
E-B, perfect fifth.
C-F, perfect fifth.
F-B flat, perfect fifth.
E-A flat, bi-equal third.*
A flat-C, bi-equal third.
A flat-E flat, perfect fifth.
A flat-D flat, perfect fifth.
D flat-G flat, perfect fifth.
G—D, D—A, A—E, three

fifths.t

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fifths, have proposed to tune the octaves a little imperfect. The objections to this are obvious, for if we sharpen the octaves to assist the fifths, it injures the thirds; and if we flatten the octaves to assist the thirds, it injures the fifths. Such is the construction of the human ear, that we can bear a much greater deviation from perfection in the fifths than we can in the octaves, and a still greater deviation in thirds than either the fifths or octayes. Again, however small the deviation may be in a single octave, it becomes very sensible in two or three, and most offensive in six or seven.

We have been in the habit of consider

tri-equaling the Wolf as an inherent imperfection in every instrument that has exactly twelve fixed keys in each septave; whereas, so far from being an imperfection, it is precisely the proper distribution of it that produces that charming variety of character between the different keys, which is so essentially requisite in a well, tuned instrument.

These tri-equal fifths, though flat, are not of such a degree of flatness as to be offensive to the ear; differing from a perfect fifth only 829,885 parts in 300,000,000, or 300000000.

82988 5 If this interval G-E, as in Kirnberger's method, be divided into one perfect fifth, and two equally flat fifths-such, for instance, as the perfect fifth G-D, and the equally flat fifths D-A and A-E; then each of these two last fifths, by becoming too flat, is offensive to the ear. And if that same interval be divided into two perfect fifths, and one flat fifth, then this flat fifth so produced is still more offensive.

In tuning each key throughout the whole instrument, too much attention cannot be paid to the beatings, as that is by far the most accurate way of tuning by the ear. For, whenever a third, fourth, fifth, sixth, or octave, is quite perfect, there is no beating to be heard. But, on the contrary, when any of them are in any degree imperfect, though not distant from perfection, a beating is always audible. A very slow beating proves that the distance from perfection is not great; but as the beating becomes quicker, the distance from perfection becomes more considerable, and, from the equality of the beatings, equal deviations may in like manner be correctly ascertained.

Some tuners, in order to assist the

A bi-equal third is thus obtained:-from one perfect octave deduct one perfect third, and divide the remainder into two equally sharp thirds.

A tri-equal fifth is thus obtained :-divide the interval included by a perfect fifth from the keynote, and the second perfect octave above the perfect third from the same key-note, into three equally flat fifths, which are tri-equal fifths.

April 8, 1836.

CORIO,

WIDENING OF BLACKFRIARS' BRIDGE.

Sir,-In Alderman Wood's recently published proposed metropolitan improvements, two of the suggested new streets terminate at Blackfriars' Bridge, and others tend towards the same point. But the question has not been consideredHas this bridge capacity for the increased traffic that would thus be attracted to it; and is it not, on the contrary, barely sufficient for the present? If it be found that the bridge is too confined, can it be adapted to meet the probable increase of traffic? These are questions that appear to me to claim the consideration of the public at a time when large sums are being expended on the repairs of the bridge, without any improvement in the roadway, either by reducing the steep ascent or giving a greater width. The accidents constantly occurring in consequence of the dangerous acclivities, will probably force the authorities to reduce them; but the widening question is not in this position. The point, however, is too important to be lost sight of. I have stepped the width of the bridge, which is about 40 feet, more or less." London Bridge, by the same mode of measurement, I made about 50 feet, the traffic

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METHOD OF MAKING CAPILLARY TUBES IN METAL.

on which is, of course, greater; yet the difference in facility of passage is as great as between Old London Bridge (which, by-the-bye, did not differ greatly in width from Blackfriars), and its nobly proportioned successor, the present London Bridge. How much did the City of London consent to pay for even an additional four or five feet to the width of the last-mentioned bridge? And it is rumoured that an increase of double that extent is practicable on Blackfriars at a comparatively trifling sum, not more, as I have heard, than a small per centage of the money now being expended on repairs, substantial repairs, I admit; but yet only repairs, not improvements, as respects the public convenience.

I am, Sir,

Your most obedient servant,
A CITIZEN.
Fleet-street, February, 1836.

METHOD OF MAKING CAPILLARY TUBES
IN METAL.

For gas-burners, for the safe combustion of mixtures of oxygen and hydrogen, and for other purposes, it is often desirable to divide the end of the dischargepipe into fine capillary tubes, of the depth of half an inch or more. It is difficult and expensive to bore such apertures in a piece of solid metal, and it is hardly possible to be executed at all, if the apertures are required to be of very small diameter.

Two new methods of producing such capillary tubes have been communicated to the Society of Arts-one by Mr. J. Roberts, of Queen-street, Cheapside, and the other by Mr. Henry Wilkinson, of Pall Mall-which are thus described in the last Part of the Society's Transactions:

Mr. Roberts's Method.

"Mr. Roberts very ingeniously and expeditiously subdivides the end of a metal pipe into small tubes of any required depth, by means of pinion-wire. Pinion-wire is made by taking a cylindrical wire of soft steel, and passing it through a draw-plate of such a figure as to form on its surface deep grooves in the direction of radii to the axis of the wire: the ribs which separate these grooves from one another may be considered as leaves or teeth, and of such wire, when cut into proper lengths, are made the pinions used by watchmakers. Hence arises the name by which this wire is commonly known. If now a piece of this wire be driven into the end of

a brass pipe of such a size as to make a close fit with it, it is evident that that part of the pipe has thus been subdivided into as many smaller tubes as there are grooves in the wire. By using a draw-plate fitted to make smaller and shallower and more numerous grooves than are required in common pinion-wire, it is manifest that wires or cores may be produced, which, when driven into metal pipes, as already described, will subdivide them into capillary tubes of almost any degree of tenuity."

Mr. Wilkinson's Method.

"In the course of some experiments on artificial light, which I was engaged in about twelve months since, I was desirous of obtaining a great number of extremely minute apertures for a gas-burner; and, finding it impossible, in the ordinary way, to obtain them, new method occurred to me, which immediately produced the desired effect. I showed it at the time to several eminent scientific men, who were unable to conceive how these apertures were formed; and, as I made no secret of the method, they were equally pleased at the simplicity of the operation; and the specimen herewith sent has been exhibiting at the Gallery of Practical Science for several months. I did not attach much importance to it myself; but, as I do not find that it is at all known, and now think it might be useful in a variety of ways, I have sent it for you to lay before the Society; and should they be of the same opinion, I shall feel much pleasure in communicating the mode of operation, by which any number of apertures, hardly visible to the naked eye, and of any length (even a foot, if required) may be made in any metal in ten minutes!

"The process consists merely in turning one cylinder to fit another very accurately, and then, by milling the outside of the inner cylinder with a straight milling-tool of the required degree of fineness, and afterwards sliding the milled cylinder within the other, apertures are produced perfectly distinct, and of course of the same length as the milled cylinder. A similar effect may be produced on flat surfaces, if required."

BOOT AND SHOE STUDS.

Sir,-About six years ago, an invention of a kind of iron studs, for increasing the durability of the soles of boots, made a great stir in the town; but its merits could but have been very imperfectly known when the manufactory in Gilispur-street was suddenly closed, and I have not been able to find that the "powerful machinery," which was said to be em loyed in the process, has been,

PORCELAIN SCALE-PLATE.

any where, subsequently brought into operation. I have just parted from the last pair of boots which I had made on this principle-not because they were actually worn out, but in consequence of their having become out of fashion.

The proprietor, or patentee, of this truly useful invention, as near as I can recollect, was a gentleman of some eminence in the legal profession, of the name of "Arabin,' or "Espinasse,” whose demise, if it deprived not the public of the benefit of clergy, certainly occasioned a lamentable vacancy in the cure of soles!

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My object in addressing you, Mr. Edi tor, is to excite the attention of those whom it may concern to the practicable revival of a contrivance so admirably calculated to maintain a respectable footing in society, and to carry us above the dirty ways of the world.

I am, sincerely, Sir,

Your most obedient servant,
HENRY BRETT.

Old Furnival's Hotel, March 25, 1836.

PORCELAIN SCALE-PLATE.

Mr. Juggins (of James-street, Covent Garden) is a dealer in butter and cheese. He states that in weighing the former it is the practice to wet the metal dish at present in use, in order to prevent the butter from adhering to it: the true weight of the butter is, therefore, less than the apparent by all the water that is put on the dish; a circumstance that, in weighing out butter by the ounce to small customers, amounts to a very sensible proportion of the whole weight.

It is also necessary, especially in hot weather, to scour the scale-dish two or three times a day, both for the appear. ance of cleanliness and to prevent the scale from giving a taint to the butter placed on it. But this frequent scouring makes the scale-dish too light, and, in order to adjust the scales, there is a constant temptation to employ contrivances which subject them to be broken when examined by the Annoyance Jury.

For the last five years Mr. Juggins has employed a plate of glazed porcelain instead of metal, by which he obtains the advantage of constant cleanliness, without the necessity of wetting the surface of the plate before using it: there is no sensible loss of weight, for this plate never requires to be scoured, but only to be

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washed or wiped; the butter receives no taint, and the evident cleanliness cou ciliates the good will of customers. The cost of one of these plates, on account of its size and thickness, is seven shillings and sixpence; but Mr. J. has not hitherto had any broken, so that with common care they will seldom require to be renewed. Trans. Soc. of Arts.

VEGETABLE OILS.

(From Report of the Commissioners of Excise Inquiry.)

Customs' Duties on the Raw Materials. Although the instructions contained in our commission do not lead us to the examination of the Customs' duties on the raw materials employed in the manufacture of soap, we trust that we shall not be considered as exceeding the proper line of our duty by calling attention to the remarks of the deputation, as well as of Mr. Fincham and Mr. Taylor, as also of Mr. Tennant of Glasgow, upon the great disadvantages to which the manufacturer is exposed from the heavy duties on importation, to which the vegetable oils are still liable. These oils would enter largely into the composition of soap, if their price were not so much increased by these duties, which amount on some descriptions to a virtual prohibition of their use. The French,

at Marseilles, employ olive oil exclusively in their soap; and in that town aloné a quantity is made very nearly equalling the consump tion of Great Britain. According to Mr. Tennant, the soap made from olive oil is better than that which is made from palm oil; and if the present duty of 41. 4s. pei ton on the former could be materially reduced, there seems to be every probability that after the abolition of the present restrictions on the manufacture, such improve ments would be introduced as would enable us to rival, and probably to surpass, the French in the North American market. Our manufactures are now placed in so disadvan tageous à situation as compared with the French and other makers, that it is very difficult for them to contend with them in the foreign markets; and even if the restrictions imposed by the Excise on the process of ma nufacture were removed, they would still suffer considerably from the duties on the materials which they employ, and on which no drawback is allowed; and it must be remembered that the difficulties under which the trade labour on this account have been materially increased by the discontinuance of the allowance of the tenths, to which we have already alluded.

The representations which were made to us on this head appeared to be so much de

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