Kingdom.]
AND SURGICAL INSTRUMENTS.
North, North Central, and South Central Galleries.
437
264 Richardson, T. W., Brede , near Northam , Sussex —
Inventor.
A reflecting telescope, for observing the sun’s surface:the reflector, made of crown glass, is part of a paraboloid
revolution.
Improved screw for straining wire fences. Hop-tallies.
Specimens of the prismatic colour on glass, &c.
265 Willats, T. & R., 28 Ironmonger Lane, Cheapside —■
Inventors and Manufacturers.
Improved portable photographic camera and stand, for°btaiuing pictures by any known photographic process, onoietal plates, paper, glass, &c.
.The advantages of this form of camera are, the facility"nth which it can be packed into a small compass; theJojustments for placing the paper or plates at the propermcus, without exposing them to the daylight; and theComparatively small weight of the apparatus: thus ren-dering the practice of photography easy to a traveller.
Improved registering thread calculator, or linen prover,
ascertain the number of threads in a given space, ofs 'lk, linen, or cotton fabric, and to register this number onPaper .
It is of importance in purchasing any woven fabric, to^certain the number of threads, warp, and woof con-tained within a square inch, as the knowledge of theseenables the purchaser to judge of its strength and dura-bility. This instrument is devised to render the operationeasy to the merchant.
266 Salmon, William John, 254 Whitechapel Rond —
Manufacturer.
Gay or night telescopes for ships’ use.
267 . Crickitt, R. E., Doctors’ Commons — Designer..Universal equatorial telescope-stand, to revolve roundne polar axis without altering, and at the same time to
secure steadiness.
268 Callaghan, W., 45 Great Russell Street, Bloomsbury
—Manufacturer.
An improved deer-stalking telescope.
A pair of portable steel spectacles.
269 Pillischer, Morrice, 398 Oxford Street —
Designer and Manufacturer.
Large and small achromatic microscopes, with the stagefoments simplified.
students’ microscope, capable of forming a portablei ' SSec ting, as well as clinical microscope, with all thennssary apparatus.
i Gouble achromatic opera-glass. Opera-glasses, mountedtortoiseshell and gilt, and mounted in ivory,any e ?6y-invented compasses, for describing ellipses of
atu' X ? thermometer in ivory, for registering maximumminimum temperatures.
2^0 Carpenter & Westley, 24 Regent Street —p. Manufacturers and Proprietors.
a n ,j an tasmagoria lanterns, with the latest mechanicals ect : °Ptical arrangements. Set of lenses, and a set ofp ° ns .°f the apparatus to show the optical principle.sut , 'Wings of natural history, with some of the sameSunii-, m outline, as printed from copper plates, andSer' art ' sts -
di«„/ e . s astronomical diagrams. Paintings adapted tolss °lving lanterns.
f 01 . m e Phantasmagoria lanterns exhibited are a scientificp r j n .°^ magic-lantern, differing from it in no essentialKited ■' ^he images they produce are variously exhi-” - e *ther on opaque or transparent screens.w hic -m improved kind of solar lamp. The manner in
ligjjt’- luler °n opaque or transparent screens. The" , hich S an ' m P rove< l kind of solar lamp. The manner in■view ^ le beautiful melting pictures called dissolvingdeserv^ 6 ^'^uced, as respects the mechanism employed,es to he explained. The arrangement adopted in
the instruments exhibited is the followingTwo lan-terns of the same size and power, and in all respectsexactly agreeing, are arranged together upon a little trayor platform. They are held fast to this stand by screwswhich admit of a certain degree of half-revolving motionfrom side to side, in order to adjust the foci. This beingdone in such a manner that the circle of light of eachlantern falls precisely upon the same spot upon the screen,the screws are tightened to the utmost extent, so as toremove all probability of further movement. The dis-solving apparatus consists of a circular tin plate, japannedin black, along three parts of the circumference of whicha crescentic aperture runs, the interval between thehorns of tke crescent being occupied by a circular open-ing, covered by a screwed plate, removable at pleasure.This plate is fixed to a horizontal wooden axis, at theother end of which is a handle, by which the plate canbe caused to rotate. The axis of wood is supported bytwo pillars, connected with a flat piece which is securedto the tray. This apparatus is placed between the lan-terns in such a manner that the circular plate is in frontof the tubes of both, while the handle projects behind thelanterns at the back. The plate can, therefore, be turnedround by means of the handle, without difficulty, frombehind. A peg of wood is fixed into the axis, so as toprevent its effecting more than half a revolution. Thewidest part of the crescentic opening in the plate, is suf-ficiently so to admit all the rays of the lantern beforewhich it happens to be placed. On the plate beingslowly turned half round, by means of the handle behind,the opening narrows until it is altogether lost in one ofthe horns of the crescent. The light of that lantern isgradually cut off as the aperture diminishes, until it is atlength wholly shaded under the moveable cover occupyingthe interval between the horns of this crescentic opening.In proportion as the light is cut off from one, it is let onfrom the other tube, in consequence of the gradually in-creasing size of the crescent revolving before it, until atlength the widest part of this opening in the plate is pre-sented before the tube of the second lantern, thefirst being, as we have seen, shaded. This movement beingreversed, the light is cut off from the second lantern, andagain let on from the first, and so on alternately. Thuswhile the screen always presents the same circle of light,yet it is derived first from one lantern, then from the next.
When in use, a slider is introduced into each lantern.The lantern before the mouth of which the widest part oithe opening in the plate is placed, exhibits the paintingon the screen, the light of the other lantern being thenhid behind the cover. On turning the handle, this pic-ture gradually becomes shaded, while the light from thesecond lantern streams through the widening opening.The effect on the screen is the melting away of the firstpicture, and the brilliant development of the second,the screen being at no instant left unoccupied by apicture.
The principle involved in this apparently complex, butin reality simple mechanism, is merely the obscuration ofone picture and the throwing of a second in the same placeon the screen. And it may be accomplished in a greatvariety of ways. Thus, by simply placing a flat piece ofwood, somewhat like the letter Z, on a point in the centre,so that alternately one or the other of the pieces at theend should be raised or depressed before the lanterns, adissolving scene is produced. Or, by fixing a moveableupright shade, which can be pushed alternately before oneor the other of the lanterns, the same effect is produced.