in order that our readers may be acquainted with all the improvements made in this important invention of the late truly illustri ous Sir Humphry Davy. The improvements proposed by Mr. Bonner in the construction of safety lamps, consist in a means of increasing the light, and of instantly extinguishing it, at pleasure. Fig. 1, plate VI. represents a vertical section of the lamp; figures 2 and 3, are plans of the top of the lamp, shewing two covers of a peculiar form for extinguishing the light: in plan 2, the covers are exhibited open; and in plan 3, shut. Fig. 4, a plan of the extinguisher; the corresponding letters in each figure have reference to similar parts.

The mode of increasing the light of the lamp is as follows: instead of introducing a wick in the centre of the lamp, as is usually at present practised, he introduces a series of small wicks round a centre tube, as shewn at a, fig. 1 and 2, and by lighting one, two, or more wicks at a time, little or much light is obtained. These wicks are placed in small tubes, fixed in a metal ring, whose inner diameter is rather larger than the outer diameter of the fixed open tube in the centre of the lamp, and the outer diameter of the ring is rather less than the diameter of the opening for the light on the top of the lamp; so that this ring with the wick-tubes fixed in it, slips easily in, and goes round the centre tube, the inner edge of the ring resting upon a narrow ledge left on the centre tube to support it, as at b fig. 1; or the outer edge of it rests on a ledge left round the opening for the light, as shewn at e; and as the ring is thereby at perfect liberty to revolve, the wicks are carried round by the trimming iron. The ring may either be level with the top of the lamp, or a little below it; but those parts of the wick tubes having the slits for the trimming, must be above the ring, and a slit made on each side of them, but not opposite each other in the same tube.

There are two methods described for extinguishing the light; the first is as follows; dd, fig. 1, gives an edge view "of two covers of a peculiar form for extinguishing the flame while unscrewing the gauze top, which is enlarged, or spread out in diameter at bottom, as shewn at ff, fig. 1, to allow room for these covers to act. The plans of these covers are exhibited in figures 2 and 3, and the light is by their means prevented from being improperly exposed. These covers are formed of two pieces of thin metal, placed upon the upper side of the lamp, upon studs or otherwise, so as to traverse and pivot on the pin or screw o, fig. 1, and o o, fig. 2 and 3; the covers may be carried over the light

so as to extinguish it, by any mechanical means; but that adopted by the patentee, is to place two or three catches on the screwring, as shewn at e, fig. 2 and 3."

The other method of putting out the light is, by an extinguisher shewn at g, fig. 1, of which a plan is given by the separate fig. 4; this is "suspended at the top of the gauze cylinder by a combustible substance, such as a piece or slip of wood, or paper, so that the extinguisher shall fall upon the light, when the combustible substance is either burnt or broken, by pressing upon the driver i. This extinguisher is formed of a thick circular piece of metal, of the same diameter as the interior of the gauze cylinder, or nearly so. It is made with two grooves to slide on two wires, hh, to guide it on its ascent and descent, which wires are secured at the upper end to the brass top, p, of the cylinder, and at the lower end to two of the outer wires. This extinguisher may also be suspended by a pin, k, to be inserted at or m, or other convenient means. A piece of wire, n, is used as a trimming wire."

BRITISH CASHMEER SHAWLS.

SEVERAL unsuccessful attempts have been made to introduce and to naturalize, in the British islands, the shawl goat of Cashmere, that variety of the common goat, or perhaps a peculiar species, the down of which is the material of the so called India shawls.

These fabrics, in fineness of fibre, lightness, and warmth, are unrivalled by those of any other material. It has therefore been considered, both in France and England, a very desirable object to introduce the shawl goat, for the purpose of ascertaining whether the climate of Europe is suitable to it, and whether, under these circumstances, the fine down given it by Nature, as a protection against the winter cold of its own country, will be produced unimpaired in the fineness of its staple.

A few years ago some shawl-goats were introduced into Scotland, but the experiment did not succeed, as they died without leaving any progeny.

From France two agents were sent to Persia, under the patronage and protection of the Emperor Napoleon, for the purpose of making purchases of goats of the Cashmeer breed, in the province of Caspahan. A considerable number of these animals was procured; and, although many of them died in their long march to the coast of the Euxine, and in their passage thence by sea to Perpignan, yet a certain number survived, and were brought to Paris by M. Terneau, in the year 1823.

VOL. IV.-NO. 75.

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1ST OCTOBER, 1829.

Mr. Tower, happening at that time to be in Paris, purchased four of them, two males and two females, and succeeded in conveying them safely to his residence in Essex.

The soil of the park at Weald Hall, where they have been kept ever since, is moist, and the situation is much exposed. The animals have, nevertheless, continued in health, and have multiplied rapidly; so that his present flock consists of twenty-seven, including the four original ones. Of these latter, a polled female, which was old when purchased by him, has every year produced at least one kid, and has twice had twins. Those individuals, of which the horns cross, are, in Persia, esteemed the best; and one of Mr. Tower's last-year kids has this peculiarity. They show no impatience of cold, and are very healthy, requiring only the occasional shelter of a shed in very rough weather. In spring, summer, and autumn, they graze like sheep, and, during winter, have been fed with hay, and refuse vegetables from the garden; but their favourite food is the gorse (Ulex Europacus), which they devour eagerly, without being annoyed by its prickles. They damage young plantations, but not more than other goats or deer will do. They breed very early; three of Mr. Tower's goats, this year, produced kids before they were themselves a twelve

month old.

A few produce brown down; but that of by far the greater proportion of the goats is white; and this latter is more valuable than the other.

The coat is a mixture of long coarse hair and of fine short down : this latter begins to loose early in April, and is collected casily and expeditiously by combing the animals two or three times with such a comb as is used for dressing horses' manes. A good deal of the long hair comes off at the same time, but the manufacturer has found no difficulty in separating it.* The produce of a male is about four ounces, and of a female about two ounces. Two pounds of down, as it comes off the goat's back, may be estimated to make one shawl fifty-four inches square; it will therefore require ten goats, male and female, to furnish materials for one shawl.

Mr. Tower has this year had three shawls made of his down, one of which was examined by the committee of manufactures. The yarn was spun by Messrs. Pease, of Darlington, and was woven by Messrs. Miller and Sons of Paisley. Mr. Tower's shawl was compared with one made in Scotland of French shawl-goat wool, to which it was evidently far superior; it was also compared with a French shawl of M. Tenneau's own make, and was considered by very competent judges to be superior to this also.

A considcrabie quantity of rough cashmeer wool was imported from India a few years ago, and baffled the attempts of the manufacturers to dis entangle the down from the hair; probably in consequence of the down having become felted in conveyiug it from Cashmeer and shipping it from Calcutta.

ECONOMICAL METHOD OF TRANSMITTING MOTION. Invented by Mr. JOHN M'DOWALL, Vauxhall.

MOTION is often required to be communicated to machinery at a distance from the first mover, and this is usually effected by a metallic shaft, which, if the distance between the machinery and the first mover be great, must be made of considerable thickness, to prevent its being twisted to pieces by the power applied, or else by chains, straps, or ropes, which, to prevent their slipping on the drums or pulleys over which they pass, causes considerable impediment to the motion by friction. These are inconveniencies which cannot in all cases be avoided; but, under some circumstances, the following method of transmitting motion, through the medium of three rods and two triple cranks, connecting the machinery with the first mover, might be introduced with considerable advantage.

The apparatus is represented with the axes of motion placed horizontally by figure 1; and with the axes placed vertically by figure 2. The same letters represent similar parts in both figures. It will be perceived that the motion may be in the direction shewn by the arrows, or the contrary; and hence the motion may versed at pleasure.

be re

Fig. 1.

Fig. 2.

The triple crank a b c, to be put in rotation by any first mover is connected by three rods to a similar crank a' b'c' of equal dimensions; and as the cranks project from the axes at equal distances there will always be one of them in a position to produce a pulling action, and hence there will be no necessity for having the conducting rods stronger than what may be sufficient to sus

tain by tension the resistance of the machine to be put in motion, and thus the expence of transmitting motion, by this method, to a considerable distance will be very small. The motion, too, will be perfectly uniform, for, as the leverage of the crank a, for instance, diminishes by its rotation, that of the corresponding crank a' will be equally diminished; so that whatever motion is produced by the first mover will be faithfully transferred to the machinery.

IMPROVED METALLIC SHUTTERS.

TO THE EDITOR.

SIR,-Every man of experience is aware it sometimes happens, in mechanical invention, that different individuals in endeavouring to obtain the same result, contrive, independently of each other, similar means of effecting it; but it is of very rare occurrence that the arrangements of the parts are, in both cases, exactly the same in all respects: happily, it is still more rare, that a man after being shown an invention, after having seen it publicly used in various places, should take out a patent for it for that purpose, making a solemn oath that the invention is a secret, is perfectly new, and was never before practised in this country. Incredible as this may appear, I trust to your candour and sense of justice to allow me to prove, that this has been done to my prejudice by Mr. Andrew Smith, the ostensible patentee, in the patent described in your last number as "granted to Mr. William Henry Kitchen, of High Street, Bloomsbury, and Mr. Andrew Smith, of York Street, Westminster, for improvements in window-shutters and doors." This patent is dated Feb. 7, 1829, and the specification was lodged in August, 1829.

Now, it was well known to Mr. Smith, that I put up publicly at Mr. Boston's, the ironmonger, in Hackney, this identical invention in the month of Sept. 1828. At that period I was the foreman to Mr. Thomas Don, the engineer, and having previously directed my attention to the improvement of his metallic shutters, I succeeded in perfecting those novel arrangements which Mr. Smith has since patented in conjunction with Mr. Kitchen.

These improvements having been shown to Messrs. Hankey, the bankers, in Fenchurch Street, they so much approved of them, that they gave directions for the metallic shutters, they had had previously of Mr. Don (constructed upon quite another principle), to be taken down from the front of their banking-house, and others on my principle to be substituted for them. This order was executed by Mr. Don, in Nov. 1828, under my directions and superintendance, and so entirely to their satisfaction, that they have recently given an order for the fitting up of another part of their premises in precisely the same manner.

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