HOUSE-BREAKER'S INSTRUMENT.

TO THE EDITOR.

SIR,-On passing through the gallery of the "National Repository" some time ago, I observed amongst the assemblage of novelties there exhibited, an instrument which is said to be employed by thieves for opening, from without, such street doors as may happen to have the keys left in their locks, inside of the house, and as I know it is a common opinion that the leaving of the key in the lock adds to the security, on the supposition that it prevents the insertion of a picklock, or skeleton-key, it is proper that the public should be put on their guard respecting the danger incurred by this supposed measure of security.

The instrument in question is merely a peculiarly formed pair of plyers, which I have delineated, with the mode of its application, in the annexed sketch. (See plate XIV. fig. 7.) a is the key of the door, supposed to be inside of the house, b the plyers, the two chops of which (technically called the nose) form, when together, a hollow cylinder; the inside of these are provided with file-cut teeth, so as to take a firm gripe of the extremity of the key when placed between them. The dotted lines, d are intended to shew the situa tion of the key-hole of the door through which the nose of the plyers is put, and when hold has been taken of the key, the chops are compressed together with great force, by turning the nut f upon the screw e. By these means the key has a firm handle on the outside of the door, and may be unlocked there as easily as in the inside. I am, Sir, your constant reader, &c. ONE OF THE NEW POLICE.

LIST OF NEW PATENTS SEALED.

PROPELLING VESSELS.-To W. Hale, of Colchester, Essex, for a machine or method of raising or forcing water for propelling vessels.-12th Jan. 1830. Specification to be enrolled in Six months.

LOCKS. To J. Carpenter, Willenhall, Stafford, and J. Young, Wolverhampton, for certain improvements on locks and other securities, applicable to doors and other purposes.-18th Jan. 1830. Six months.

RECIPROCATING ACTION.-To W. Parr, of City-road, for a new method of producing or reciprocating action, by means of rotatory motion, to be applied to the working of all kinds of pumps, mangles, and all other machinery in or to which reciprocating action is required, or may be applied. 18th Jan. 1830. Four months.

MACHINERY.-To E. Dakeyne, and J. Dakeyne, Derby, for a machine or hydraulic engine for applying the power or pressure of water, steam, and other elastic fluids, to the purpose of working machinery, &c.-21st Jan. 1830. Six months.

DESCRIPTIVE ACCOUNT OF ALL THE

PATENTS ENROLLED BETWEEN 20TH JANUARY AND 20TH FEBRUARY, 1830.

Particularizing the Offices in which the Specifications may be inspected, with the Dates of Enrolment.

DRESSING CLOTH.-To Joseph Chisild Daniell, of Limpley Stoke, Bradford, Wilts, clothier, a patent for " certain improvements in machinery applicable to dressing woollen cloth," was granted on the 8th of July, 1829, and the specification was deposited in the Enrolment Office on the 8th of January, 1830.

It will be recollected that Mr. Daniell specified, in March last, a patent for improvements in machinery applicable to dressing cloth, and another for improvements on the first patent on the twenty-fourth of last November, described in the January number of the Register of Arts, p. 163; and the present is a patent for an improvement on the last, consisting in the introduction of adjusting screws under the spring of the card-board, and also a slight modification in the rollers which conduct the cloth to and from the gig-mill.

That it may answer this gentleman's purpose to expend several hundred pounds on patents for these trifling improvements on improvements we are not prepared to deny, but we confess our inability to see their utility. Before he had specified his patent in March, he must have had another in progress for inventions which might have been included in the first, for the title was sufficiently general to include them; and long before he specified the second, he had in progress the third for improvements, which evidently belonged to the second. Mr. Daniell seems perfectly ignorant of the six months which usually intervene between the sealing and enrolling of the patent being given for the very purpose of completing experimentally the invention for which the patent. is granted.

GENERATING STEAM AND CURRENTS OF AIR.-To Moses Poole, of Lincoln's Inn, London, a patent for "certain improvements in the apparatus for raising or generating steam and currents of air, and for the application thereof to locomotive engines. and other purposes," was granted on the 8th of July last, and the specification was lodged in the Enrolment Office on the 8th of January, 1830.

This invention is said to have been communicated to the VOL. IV.-No. 80. 1ST MARCH, 1830.

G G

patentee by a foreigner residing abroad, and this circumstance must account for the specification containing principally arrangements already patented, published, and abandoned by the patentees. The steam-boiler described, consists in a series of straight tubes placed horizontally, some under, others over, and some on each side of the fire. The first tube is joined to the second at one end, and the second is joined to the third at the other, so that the whole boiler consists, in effect, of one continuous tube. Through this the water is driven by a forcing pump, and when sufficiently heated it is admitted into a vessel called a separator, and thence conveyed to the working cylinders. From the cylinders the steam is conveyed still in a highly elastic state to a reservoir, from which it escapes by four very small apertures up the chimney, carrying with it the air in the chimney, and by that means creates a current, which may be increased or diminished at pleasure by an alteration of the apertures through which the steam escapes, which apertures must never be so large as to allow the steam to escape from the reservoir so fast as to diminish its elasticity, a circumstance which would cause an irregularity in the passage of the steam, and consequently of the draft of air through the chimney.

When this apparatus is applied to a locomotive carriage, it is necessary to supply water to the boiler before the carriage starts, as well as during occasional stoppages, which the patentee proposes to effect by hand, or by lifting the wheels off the ground, and then working the pump by the engine, as the wheels may then turn without propelling the carriage. The carriage is lifted by a lever extending from the axletree, or a fixed point near it, and reaching a few inches farther than the circumference of the wheel; and when this lever is brought directly under the wheel, by winding a chain from it on a drum, or drawing it by a piston in a small steam cylinder, the wheel is at liberty to turn freely. This is really the most cumbersome and clumsy method of putting machinery out of gear which can well be devised; but the patentee proposes to use the same contrivance as a drag to impede the progress of the carriage when descending hills.

MEASURING TAPES.-To James Chesterman, of Sheffield, Yorkshire, mechanic, a patent for "certain improvements in machines or apparatus for measuring land and other purposes," was granted the 14th of July, 1829, and the specification was lodged in the Enrolment Office on the 14th of January, 1830.

A very few words will suffice to describe this invention, as it consists in the application of a coiled spring, similar to those used for watches to the axis of a measuring tape-box; and if the tape be long, a train of wheels is introduced to produce a greater number of revolutions in the axis by the uncoiling of the spring. We need scarcely mention, that the use of the spring is to wind up or draw in the tape after it has been applied to the space to be measured.

COACHES.-To Thomas Brown, of Birmingham, a patent for "an improved coach," was granted on the 5th of August, and the specification was deposited in the Enrolment Office on the 5th of February last.

The object of this patentee is to construct a coach of the stage kind, which shall be lighter without being weaker, and at the same time easier drawn, less liable to be upset by irregularities on the road, and freer from jolting motion than stage-coaches of the usual description.

These desirable qualifications he proposes to obtain by the introduction into one coach of a variety of improvements, which have been individually designed and separately applied to different coaches. The lower framing of the coach body is made sufficiently strong to admit of the axles being attached to it without the intervention of a perch or lower framing, and thus lightness is obtained. The springs, four in number, are fixed to the axles, and made to pass horizontally along the side of the coach; and this circumstance, together with that of depositing the greater part of the load very low, is stated by the patentee to obviate much of the jolting motion experienced by passengers.

The load is brought lower by having the axle of the hind wheels bent into a crank form to admit the body of the coach to reach near the ground, by this room is obtained for luggage, as well as for the feet of the inside passengers."

It would be difficult to point out in these arrangements any thing new. Mr. Brown does not, however, lay claim to any of them separately as his invention, but only as his method of uniting the whole to form a stage-coach which shall possess the advantages above enumerated.

EXTRACT OF COCOA.-To John Marshall, of Southampton Street, Strand, London, tea-dealer, a patent for a method of preparing or making an extract from cocoa, which he denominated

Marshall's Extract of Cocoa," was granted on the 10th of December, and the specification was deposited in the Enrolment Office on the 10th of February, 1830.

Mr. Marshall's invention consists in boiling for an hour a pound of powdered cocoa in a gallon of water. The mixture is then to be passed through a sieve, and the oily matter skimmed from the surface. It is next to be evaporated in a water bath till it assumes the consistence of treacle, when it is to be preserved for use in bottles well corked and sealed, so as to render them impervious to the air.

TILES. TO Francis H. N. Drake, Esq., of Colyton House, Devon, a patent for "improvements in tiles for houses and other buildings," was granted on the 25th of July, and the specification was deposited in the Enrolment Office on the 25th of February.

This improvement may be briefly described to consist in making the upper ends of the tiles, whether of the flat or pantile kind, so thin that the lower tapering ends of the next row of tiles fit upon them, by which a smooth surface is obtained, which will prevent the tiles being raised and blown off by high winds. On each side of the tiles grooves are made for the passage of water, and the shoulder, to which the upper tier of tiles lap over, is made to bevel or slope from the middle downwards to convey the water into the side grooves.

The patentee describes the method of making his improved tiles, which, as it does not essentially differ from that generally used, we have deemed unnecessary to detail.

SHARPENING KNIVES.-To Francis Westby, of Leicester, cutler, a patent for "certain improved apparatus to be used for the purpose of whetting or sharpening the edges of the blades of razors, penknives, or other cutting instruments," was granted on the 26th of November, and the specification was deposited in the Enrolment Office on the 26th of January last.

The improvements proposed by Mr. Westby consist in the application to a hone or oil-stone of a guide to keep the edge of the razor or other cutting instrument at the same angle with respect to the surface of the hone during the operation of whetting. This is effected in two ways: first, by placing over the hone a plate of metal extending its whole length, and adjustable, at any required distance parallel to its surface, by set screws. Now, in the operation of sharpening, the back of the instrument is kept