1485
°''der to obtain the most perfect form of the compen-ton, Mr. Loseby selected the following as the principal^nnautons to be observed. That its rate of increase shouldcr'. eU P‘e law required; that its action slionld notfriction; and that it slionld only act throughJI P“ r t of tlte arc in which it was required, so as to' ts entire effect on the vibration to the lowest pos-1 le amount, in order that it may not sensibly diminisharc, mu- require any addition to the compensation for
temperature.
°“ n 'veting spring is composed of watch balance-!' | nig wire, and the small force required affords a prac-M'al illustration of the slight momentum necessary tojiiodnce a considerable difference in the time of thePendulum ’s vibration.
1 he third improvement has for its object a more advan-“ffcotts form of the pendulum, which is effected by pack-n ff the ends of the vessel containing the mercury withSci * w stuffing-boxes.
As the only test by which improvements in horologyan be judged of is that of actual trial, and as the Reportstl , a Astronomer lioyal to the lairds Commissioners of« Admiralty on Mr. Loseby’s improvements are too longinsert here, we would refer our readers to a pamphletJ 1 Pie subject published by Effingham Wilson, lioyal^change.
Registered under the Protection of Inventions Act.—1 • 408 .
[1 lie term “ isochronous,” in its simplest mode of de-"ition, is the performing of several acts in equal times;® uc li as the vibrations of the pendulum of a clock, orMi balance-wheel of a watch. Upon the performance ofl(i same act with unvarying regularity depends theej tcellence of chronometers and other machines for the•Measurement of time. The number of vibrations in an°'ir varies with the temperature; and to produce thed, Ue number of vibrations in a given time under ull tem-I’lii atnres and in all climates has hitherto been a deside-ratum earnestly sought after, and all but realized. In the1'osecutioii of the inquiry as to the best means of se-complete regularity, we find the names of Ilar-^ S °H and Madge, Earnshaw and Arnold, Arnold andu "i &e. &c. Sic.: these have produced chronometersQuailed in excellence by the makers of any otherMm. The means employed to arrive at the desiredbal 1 * la ' e ' ,een var ' ous: 'he majority have employed() j, lll i c es, the outer rim of which is formed by the uniont"o metals, such as steel and brass, divided in its"inference into two or more parts, and attached tobar or “crossing” by opposite ends, leaving thet j^ ers free to operate. Increase of temperature expands0 j. s bMd, which causes a loss of time; the same degreetij 'nnf operates differently on the brass which forms\vp O . UT0r 1'art; cold increases the elasticity of the steel,. ph would cause the mahine to gain, but the brasstli e * tS ,P ecu 'uu' property again operates and counteractstlie °^ ect “fining therefrom. Weights are attached to
Sci 'ewi
t- outer portion of the circle in the form of four smallSat^"' 6 ’ “iteration of which aids the desired eompen-is " M’hatever arrangement or combination of metals’MHi""' 1 - 1 ’ 'be end sought is the production of an isoehro-beat 01 aS Moni'ly as possible an unvarying and regularlH'ot ° l v '' )1 'a'inn. The present exhibitor wishes tobier UCe t ' l ' s by the employment of tubes containingHi C ".'y> in the manner described by himself in the enu-.Mitiou of the articles exhibited.
' 111111 ° SU °' 1 a of accuracy have the makers of chro-
tetn “ffifctl) that several carried to the most oppositelea >l . aturcs have not been found to vary two seconds offorth* 11 ! 10 "'fougbont the year. 30(1 1. is awarded annually
M'eati time thr<
for tl le i -.
^ ,es t; they are tested at Greenwich Observatory.
■A.]
32 Jackson, W. II. & S., 66 lied Lion Street, Cler/iemcell— Inventors and Manufacturers.
Sections of watch movements, showing the constructionof the solielave or solid key watch.
Face and back of a watch, elaborately engraved andornamented.
The right-hand section represents the inside view ofthe pillar plate of the watch movement showing thecalibre.
A is a barrel containing the main spring.
11 is a hollow square arbor planted in the frame, havinga leverage the entire depth of the movement. This, in atoothed barrel, is in action only during the time of wind-ing up the watch.
The middle view is a lateral section of the watch move-ment.
E is the barrel containing the motive power.
E, hollow square arbor as planted.
/the key with solid square.
The left hand view represents the pillar plate under thedial.
0 is a steel toothed wheel on the extremity of the wind-ing arbor containing a hollow square (closed at this endto prevent the passage of any substance into the move-ment').
1) is a similar wheel on the fuzee or barrel arbor, as theease may be, driven by 0, and by which the main springis wound up.— 1\ 411,—Plate 307.
[The objects of the application of the solid key forwatches are to effect economy in production, and to attainmore elegance of form, with equal solidity of parts, andto simplify the winding. Much saving may he alsoeffected both in the cost of the material of the watch-easewhen of gold, and in the outlay of labour. In a watchas usually made, the case, besides the inner cover to themovement, has a stout outer cover, with a joint or hingeof fine workmanship, and fittings with secret springs, &e.,all required to protect the winding aperture from dust,&c. In the solielave or solid key watch, this additionallabour, thickness, and expense, are dispensed with, as thewatch is wound by a solid square directly from the out-side,—the small aperture for the key being isolated andleading to no part of the watch, by whose friction theaccuracy of its time-keeping can be sensibly affected.]
108 CoLLAtui & Coi.i.Aiui, 20 Cheapsuie —Inventors,Patentees, and Manufacturers.
An extra grand pianoforte, of seven octaves, A to A,with the new patent repetition action, in a case of thechoicest specimen of llritish mottled oak, richly deco-rated with carved and gilt ornaments in the style ofLouis XV .
(This instrument was exhibited in the Western Nave,under the east-iron dome of the Ooalbrook Dale Com-pany.)
An elegant extra grand pianoforte of 7 octaves, A to A,with the [latent repetition action, in a choice rosewoodease, with elliptic end, carved plinth, and richly carvedcabriole trusses.
A cabinet pianoforte of (ij octaves, with the new [latentrepetition action, in a ease of rich llritish oak, of a verynovel and beautiful design, richly carved in the style ofLouis XV .
A square semi-grand pianoforte, of (if octaves, withthe patent repetition action, in a ease of very fine walnut-tree, on handsome truss legs and paw feet, decorated inthe Florentine style with richly carved festoons, andcentre panels of palm branches entwined with wreaths oflaurel.
Two microchordons, or, semi-cottage pianos in plaincases of pine and rosewood, submitted as specimens ofvery superior instruments of their particular class, atprices so low ns to lie within the reach of a very numerousclass of purchasers who might otherwise be driven to thealternative of buying inferior instruments.