of obtaining in sufficient abundance the means of ascertaining the weight of the coinage; this want, however, has been promptly met, and among other sovereign remedies, a balance (invented by Mr. W. Armstead) brought out by Mr. Kershaw, of Wilderness-row, is deserving of especial notice, alike for its ingenuity and power.

This instrument, which has been appropriately named the "Micrometer Balance," is represented in the prefixed sketch. It consists of a beam or steelyard AB, supported on a knife-edged fulcrum at c; about midway on the cylindrical portion of the beam (в) a few threads of a screw are cut, upon which a micrometer wheel D, tapped to correspond, turns freely; the rim or periphery of this wheel is divided into half grains, each of which extends over a space equal to one quarter of an inch.* When at rest, the end of the beam B rests upon a pillar or supporter E.

To use this balance, the micrometer wheel is turned back towards B, until the zero, or full-weight mark, is immediately under the index bar G. If the coin is deficient, the wheel is turned forward until equilibrium is obtained, when the value of the actual deficiency will be shown in pence by the figures on the periphery of the wheel. When half.. Sovereigns are to be tested, the supplemental weight f is employed, when the deficiency will be indicated as before.

By this balance the use of small weights and the necessity of calculations are entirely obviated, and the ease with which the deficiency in the value of the coin can be detected must recommend it to all persons having money passing through their hands.

This method of ascertaining in a distinct and tangible manner very minute differences of weight is both ingenious and useful, and will very soon be applied to balances for several other purposes for which it seems to be peculiarly eligible.

The greater portion of the "light gold" has by this time been put out of circulation; but there is reason to believe that a good deal is still in reserve, to be passed current when the present excitement has subsided. Besides which, the ordinary wear will be going on, (to say nothing of wilful deterioration,) and

By increasing the diameter and diminishing

the thickness of the wheel, a still larger indication can of course be obtained.

A is a guide-ball, of wood, which forms the top of the machine, made hollow for the sake of lightness, and so hung as to turn completely round on an iron rod B. The iron rod B is inserted into a brass box C, and so connected, as to revolve round and bend in any direction. A spring is placed in the box C, which causes the rod B, when there is no pressure upon it, to return to its vertical position. D is the brush-head, made of wood, into which is inserted all round five rows of whalebone. E is a brass socket, into which the lower end of the brush-head is fixed, and from the bottom of which projects a screw, e, which, for about one-third of its length at the lower end, has in the vertical direction cut away, as shown separately on an enlarged scale in fig. 4. F is another socket, with the

hollow part the reverse way of that of E, from the top of which projects a screw of a similar description with the last, so that the two half-ends, ef, meet and fit each other exactly. T is a thimble, with threads inside corresponding to those of the screws, which is brought over the two half-ends, and connects them firmly together. G' is a piece which is inserted at one end into the socket F, and at the other is shaped like B, and connected in the same manner as that is, with a brass box and spring G2, so as also to revolve round and bend in any direction. G3 is an under piece, which screws on to G2, and terminates in a socket, into which the cane piece H is fixed by a screw, in the manner represented in fig. 2. Where a number of cane pieces are required, they may be either jointed in the ordi

nary way, or by screws and thimbles, like those before described, (e ƒ T.)

The superiority of this machine, in several respects, is very evident. The guide-ball, in ascending a flue, by revolving in any direction, is enabled to pass easily over any irregularities or projections, and its universal joint allows it to turn much sharper angles than what a common machine can do. Again, the universal joint at G', G2, G3, brings the cane, or series of canes, readily into work; while the new screw joint, (a contrivance of great ingenuity, and applicable to many other purposes besides the present,) effectually excludes all risk of the brush being detached from the other parts of the machine, as happens but too frequently with Glass's, and other machines,

From a number of well-authenticated experiments, made at Sheffield with this apparatus, it appears to require only about one-half the power of those in com

mon use,

THE WATER SUPPLY OF THE METROPOLIS, AND MR. STUCKEY'S PLAN OF FILTRA

TION.

We have been favoured with a copy of a petition which, we are glad to find, was presented on Monday last to the House of Commons, by that zealous friend of all public improvements, Major-General Sir Frederick Trench, from Mr. Stuckey, the inventor of the new system of filtration which has been recently the subject of several interesting communications in our journal.

The petition, after reciting the different parliamentary inquiries which were instituted into the subject of purifying the water of the metropolis in 1821, 1828, and 1834, states that, from the evidence elicited by these inquiries, it appeared

:

"That Filtration as then carried on (and as it is still carried on), was most dilatory in its process, and most expensive in its results:that it had ruined one great Water Company in the City of Glasgow:-that it had entailed a cost of fifteen per cent. upon the rental of the Chelsea Water-works Com. pany that it would take £19,000 per annum, or double the per-centage of the Chelsea Company, to filter the water of the New River Company :-that the charge estimated by the Engineer of the East London Water-works Company, was no less than 11 per cent. upon the rental of that Company, (the greatest part of the water of which was used for manufacturing pur

poses,) and most of those Companies, with many others, though strongly urged by Committees of your Honourable House, by public opinion, and by the acknowledged inferiority of the supply in its unfiltered state, have refused, and up to the present hour continue to refuse to filter their water, on the ground of the dilatoriness of the process, and the enormity of the expense."

The Petitioner further avers "that seeing the necessity of filtration, though declining to do it themselves, many of those Water Companies have urged, that their customers possess private filters, and that such private filters, by filtering the water wanted only for domestic purposes, might more economically purify the water necessary to be purified, than those Companies could do it for them :-but, that such small filters, by the slowness of their process, destroy the carbonic acid gas which is contained in the water, and without which it speedily becomes offensive, putrid, and injurious to health; but, that by the filter he has invented, the carbonic acid gas is retained in the water; and moreover, that by the present system of filtration, it requires large quantities of ground to be set apart for filtering beds, which have frequently to be cleaned, at great expense, attended with malaria, often fatal in its results :-whereas, by the petitioner's process of filtration, one foot will do the work of one acre of such filtering beds, without the necessity of frequent periodical cleansings, and without the possibility of dangerous malaria."

The petitioner sums up the advantages of his invention over the present system of filtration, in these words:

It presents an economy in SPACE of one foot for one acre of MONEY, of £7,300 per annum as the current expenses, instead of the estimated current expenses of the New River Company of £19,000 per annum; and in TIME, of filtering in 6 hours by machinery of one foot to the acre, more than two millions, three hundred thousand gallons, which quantity, in the Chelsea water-works, it takes twenty-four hours to filter."

The petitioner concludes with the mention of a personal circumstance highly honourable to Mr. Stuckey, who though descended of English parents, was, it appears, born in Russia.

"The petitioner has no wish either to manufacture, or to receive any profit upon the manufacturing of his machines, but on his return to his native country (Russia), will be perfectly satisfied by the adoption by the land of his fathers of this valuable invention, upon any terms its legislature may think proper.

"The petitioner has not taken out a pa

tent for his invention for filtration, considering that a manner of such vast importance to millions of his fellow-creatures should not be limited in its operation by the exactions of monopoly, or the avarice of that inhumanity which would refuse the blessing of pure water to all who would not, or could not, enrich the discoverer of such an invention."

The prayer of the petition is, for an inquiry into the truth of its allegations, and should such inquiry terminate to the satisfaction of the House, that they will "take means to provide for the universal adoption of filtration, upon the petitioner's plan, for the benefit of the hundreds of thousands of families who have petitioned the House for pure water."

ABSTRACTS OF SPECIFICATIONS OF ENGLISH

PATENTS RECENTLY ENROLLED.

JAMES COLE, or No. 2, YOUL'S PLACE, OLD KENT-ROAD, IN THE COUNTY OF SURREY, BRUSH MANUFACTURER, for certain improvements in the construction of brushes. -Enrolment Office, July 15, 1842.

The usual modes of making brushes and brooms are technically called pan and drawing. According to the first of these modes the bristles are set into the wood by means of pitch, cement, or glue, (generally pitch) kept in a heated state in a pan over a charcoal fire; while, according to the second mode, they are drawn into the wood by being passed into a loop of wire which tightens as it is pulled, until the bristles get firmly fixed in the hole; after which, the wire is passed through the next hole, a loop made for the bristles, and so on, until the brush is complete. In the former case, it is the pitch, cement, or glue, that holds the bristles fast; in the other case it is the wire.

The first of the present patented improvements consists in securing the bristles independently of the pitch or wire. In explaining how this is accomplished, Mr. Cole treats of the operation under three heads; first, the boring of the holes; second, the making of the knots of bristles; and third, the inserting of the knots. First, then, of the boring of the holes. The hole made for pan-work is only a semicircular excavation in the solid face of the wood. In drawn work there is a similar hole with a smaller one from the bottom of it right through the wood. For his improved method, Mr. Cole adopts the drawn work hole inverted, but with a less disproportion between the two orifices. As in drawn work in certain cases, a taper hole made with one bit answers, instead of making the two holes by

separate operations; so also in his method, one bit cutting a taper hole, will, in many instances, answer instead of using two bits. The main distinction, however, between the hole, Mr. Cole adopts in his new plan, and that common to drawn work is, that he uses the hole in an inverted position. In drawn work the largest part of the hole is on the face of the brush, while in brushes of his improved description, the largest part is at the back of the brush. Secondly, of making the knots of bristles. A knot is the techni

cal term for the quantity of bristles with which each hole is filled. In drawn work the knot is formed by the action of the wire and held in by it. In pan work the knot is formed by taking as many bristles as will fill the hole, and dipping the root ends into melted pitch, cement, or glue, to the depth of th or 4th of an inch. The superfluous pitch, cement, or glue, is then cleared off by drawing the knot over a thin edge of metal, called a striker, and the bristles thus cleared are all bound together by a piece of thrum, or hemp, being wound tight round the part which has been so dipped. In the same manner as that last described, Mr. Cole makes the knots for his improved construction of brushes. But, thirdly, as regards the insertion of the knots into the wood: according to the method ordinarily followed in pan-work, when the knot has been dipped and bound together in the manner just explained, it is dipped a second time into the pitch, cement, or glue, and with all the pitch, cement, or glue, which adheres to it, is immediately inserted in the hole; the pitch, glue, or cement used, being the only thing that attaches the knot of bristles to the wood. Now, Mr. Cole's improvement as regards this part of the operation, consists in not dipping the knot a second time, but binding the whole of the bristles together by winding a piece of thread loosely round them from the root upwards to the flag, and then passing the knot so wound up, flag foremost, through the hole at the back part and pulling it through, until the part pitched and bound together fills the cavity prepared for it. He then pulls out the loose thread, which was only put on for the convenience of passing the knot through the hole easily and speedily. A knot secured in this manner cannot afterwards be pulled out without breaking the wood that holds it together. But, as there is nothing in the form of the hole to prevent it from being pushed back again, in order to guard against this after all the holes in the brush have been filled in the manner before described, the patentee takes a red hot iron and burns away all irregularities of pitch, bristle, or thrum, to a level with the wood in which they are inserted, and then affixes to the sur

face so levelled, a back of wood or other material, nailed, glued, screwed, or otherwise fastened to it, by which backing, any pushing back of the knot is effectually prevented. By this his first improved mode of construction, he combines the two advantages which separately distinguish the pan and drawing methods, and is able to make brushes of a more effective and durable character than can be made by either.

A second improvement consists in subjecting the string with which brushes are tied to a previous preparation, whereby the bursting so much complained of when brushes are laid in water, to prevent the paint on them from hardening, is effectually prevented. The composition which he uses is made as follows:-To the article known in commerce by the name of the "British American fluid," he adds as much caoutchouc in solution as it will take up or combine with. The fluid is slow in taking up the caoutchouc, and he states that he has not not been able in any of his experiments to saturate it completely until the mixture has stood five or six days. When thus prepared, he immerses the string in the preparation and leaves it in, long enough for it to become saturated with it. He then draws it out, clears it of the superfluous fluid and dries it.

A third improvement relates to that class of brushes in which the handle is inserted in the form of a wedge as in the painting brush, tar brush, dusting brush and others. The handle is the only stay for brushes so made, and from the nature of the wedge it is plain that the least relaxation from the tightness imparted by the last drive of the hammer endangers the whole brush. There is a moisture in bristles which long exposure to a warm atmosphere dries up, and it is a matter of every-day occurrence that through this drying up, the handles of brushes so made, get loose and the brushes fall to pieces. To remedy this, Mr. Cole adopts the following means:-After the brush is made in the usual manner, he submits it to an artificial heat, to shrink the bristles as much as possible. He then takes a square staple of metal as wide as the thickest part of the wedge handle, and with prongs as long as the binding on the brush, and drives these prongs through the body of bristle that has been shrunk, until the bar of the staple rests upon the top of the wedge, and the points of the prongs appear through the bristles at their roots, or in other words at the back of the brush. He then takes a thin plate of metal of the same size as the back of the brush, having a hole in the centre sufficient to enable it to pass freely down the handle, and having also holes for the reception of the prongs of the staple; and having passed

this plate on to the handle and prongs, he secures it to the staple by soldering or rivetting. The bristles being thus artificially shrunk, and the laxity thus produced being made good by the prongs of the staple passing through them, the brush is rendered extremely tight, and the staple crossing the top of the wedge, and being secured by its prongs to the plate at the back, keeps the brush so; because the staple so confined cannot slide back from its position, nor can it allow the wedge to do so in the least degree.

A fourth improvement consists in constructing in the following manner brushes of plush for cleaning ladies' garments and other slight fabrics, the texture of which might be injured by the friction of bristles. The patentee takes a piece of plush of any convenient length and width (say 6 in. long and 6 in. wide) and forms it into a cylinder having the grain of the plush running round it. It is then closed at one end, and white flock or other suitable material is stuffed into it. When thus stuffed the upper end is closed after the same manner as the lower end. To hide the gatherings at the ends, the patentee covers button-moulds of a convenient size with silk or other material, and affixes one at each end of the brush.

One

A fifth improvement consists in making brushes or pencils of spun glass, by which aqua fortis and other corrosive acids can be applied by silversmiths and jewellers with more delicacy and safety in testing metals, than by any of the usual means, and which can also be made available for many useful purposes in chemistry and the arts. form in which he make brushes of this sort resembles, in some respects, the well-known camel-hair pencil; but instead of the quill there employed, he makes use of glass tubes, preferring to have them tapering off in diameter at the end designed for the brush. The spun glass being cut into convenient lengths, he passes a knot or bunch of it down the tube, until it comes out of a convenient length at the other end. If the tube is well filled and a good length of the knot is left inside, no additional fastening will be required; but for the sake of greater certainty, that portion of the tube which immediately surrounds the knot of glass may be softened by means of the blow-pipe and then compressed and elongated a little, so as to tighten upon the spun glass, taking care not to allow the flame of the blow-pipe to touch the spun glass, which would be fused or injured by it. Another mode of securing the spun glass, is to make use of a tube of a tapering form, and drawing the spun glass through the smaller end, till it can be drawn no further, then to plug up the vacant