148G

OFFICIAL DESCRIPTIVE AND ILLUSTRATED CATALOGUE.

The preceding instruments illustrate the followingpatents taken out by, and assigned to, Messrs. Collard andCollard.

For “ Certain improvements in pianofortes, and in themode of stringing the same,” viz., an application of thecheck action to the square pianoforte, thenceforwardcalled the Grand Square; and a new mode of stringing,adapted to instruments of all kinds, hy passing the wireround a single pin; thus superseding the use of the nooseor eye, before in general use ; also for a new arrangementof the damper, known as the elongated damper-head, hywhich the jarring consequent on the old method was en-tirely prevented, and more effectual damping secured.Patented March 2, 1827.

For “ Improvements in Upright Pianofortes,” viz.,applying a check to the under hammer to prevent therebound of the hammer against the string. PatentedNovember 2, 1829.

For “ Improvement in the Mechanism of HorizontalGrand and Square Pianofortes,” consisting of an entirelynew construction of the action, the escapement beingplaced upon the key, and coming in contact with a leveror crank, and thus regulating the rise and fall of thehammer, thereby imparting greater vigour to the blow,and increased durability to the touch. Patcuted January15, 1835.

The introduction of a new class of square pianoforte,entitled, “ the Patent Square Semi-graml Pianoforte,”being a further improvement of the grand square, bywhich a closer approximation to the peculiarities of thehorizontal grand pianoforte was attained. PatentedJanuary 1, 1838.

For “ Certain further improvements in the Action ofHorizontal Pianofortes,” consisting of the introduction ofthe traversing escapement fixed upon the hammer-rail,resulting in a greater amount of precision and increasedvigour of action, as also the introduction of a repetitionmovement. Patented November 11, 1841.

For “ Improvement in the Action of Pianofortes,” viz.,the application of the repetition movement to square andto vertical or upright instruments. Patented April 29,1843.

Registered—A new design for the shape of a squarepianoforte, entitled, “ the Symmetrical Grand Square,"by which greater beauty of form was secured, the key-board being placed in the centre of the instrument, thusobviating the inelegant appearance of the old instruments.Patented October 15, 1847.—1>. 430.—Plate 321.

097 Walker, John, 48 1’rinccs Street, Leicester Square—Manufacturer.

Drawing room clock-case, from a design by Mr. 0.Grant; with subjects in panels embossed by Mr. G. Abbott.The case is electrotyped, and consists of a base andpedestal of turquoise blue glass, surmounted by figuresindicating the progress made in the civilization of thisisland, which is also illustrated by the 7 panels revolvingat the base. These subjects represent the savage life ofthe ancient llritons—the Roman governor introducingagriculture—the encouragement given to Flemish weaversto settle in the island;—the introduction of printing hyOaxton —the improvement of the steam-engine by JamesWatt —the opening of the first railway at Liverpool—andthe movement which led to the Great Exhibition.-P. 472*.—Plate 337.

752 Cotton, William, Governor of the Hank ofEngland, Lotulon.

A coin weighing-machine for sovereigns or half-sovereigns, which performs the various operations ofweighing the coin, and separating it into two classes,viz., light, and full weight. It consists of a squarebrass box ; on the top of which is placed a hopper, to holdthe sovereigns to be weighed. This hopper is a longtrough, placed at an angle of about 45° with the top ofthe box : it will contain about 500 sovereigns. In frontof the box are two small apertures, to which are fitted tworeceivers, one for the sovereigns of full weight, the otherfor those which are light. Inside the box, and near the

upper plate, the beam or balance is placed ; at one end ofthe beam, and above it, a small platform is poised upon aknife-edge, which receives the sovereigns to be weighed:this platform, which, in fact, is one of the scales, is keptin its position hy means of a small pendulum, in which,at about an inch below the platform, there is an oblongperforation, about half an inch in length, technicallycalled a “slot,” in which a small ivory rod works freelyup and down without touching the sides.

Retween the slot and the platform a pair of forceps isplaced. From a knife-edge at the other end of the beama small round polished plate is suspended, to which apendulum is fixed, and at its lower part the scale is placedto receive the weight. Above the small round plate,under the top of the box, an agate is fixed, with a bluntpoint. When the machine is in motion, the small ivoryrod is depressed ; this, on touching the bottom of the slotor opening in the pendulum in which it works, bringsdown the beam on that side, and raises it on the other,the weight side, until the small round plate on that sidetouches the agate point. The beam is then in a horizontalposition. As soon as this is effected, the forceps catchhold of the pendulum between the platform and the slotand hold it firmly. The balance is then in a condition toreceive the sovereign, which is shifted from the bottomof the pile in the hopper, and brought hy means of a slidealong a channel just large enough for a sovereign of theproper standard gold to pass, but not large enough toadmit a counterfeit, and deposited upon the platform.The forceps then let go their hold, the ivory rod is gentlyraised, and, if the sovereign happens to be light, that emlof the beam rises, and the other leaves the agate point;but if the sovereign be of full weight, the beam remainsstationary, and the small plate on the weight end incontact with the agate point.

When the sovereign is weighed, the operation of its re-moval is very ingenious, and is as follows:—Two boltsare placed at right angles to each other, and on each sideof the platform or scale there is a part cut away to admitof the holts striking so far into the area of the platform asto remove anything that would nearly fill it. 'These boltsare made to strike at different elevations, the lower onestriking (as to time) a little before the other; if thesovereign he of full weight, the scale remains down, and thelower bolt knocks it off into the full-weight box. If thesovereign, on the other hand, be light, it rises up, the firs*'bolt strikes under and misses it, and the higher bolt thenstrikes and knocks it off into the light box. This machineweighs about thirty-three sovereigns in one minute. 'Theweights used are of glass, and are adjusted to within theten-thousandth part of a grain.

753 C it ALLIS, Professor, Observatory , Cambridye —Inventor.

An instrument for calculating the sum of the correctionsof the three errors of a transit instrument, adapted for thelatitude of Cambridge, ami for any given north pola' 1distance. The manner of performing the calculation i sdependent upon certain geometrical considerations, fullydetailed in the Monthly Notices of the Royal Astro-nomical Society, Vol. 10, No. 8.

'The instrument consists of a brass circular plate, move-able about a vertical axis, passing through its centre; onthe plate are engraved scales for setting off positive andnegative level and azimuth errors. A straight edge guidesthe motion of two bars, which carry two tine parallel,threads of blackened unspun silk over the surfacethe plate. 'The interval between the threads is madeequal to the collimation error hy means of a scale engravedon a brass plate to which one of the bars is attached, andan index fixed to the brass plate to which the other ba>is attached; the two plates are clamped together by 11screw; when the threads are set to the required interval)the screw-head serves for a handle by which to movethem. The circle is graduated for showing north l»d‘ udistances both above and below the pole. The calculatin'!is performed simply as follows. After setting the circ nto a given north polar distance, one of the threads is madeto bisect a dot whose co-ordinates are the level a"