Class X.] SPECTACLES AXD OPERA-GLASSES ; DISSOLVING VIEWS APPARATUS.
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more than exhibit a collection of shop goods, and haveregarded the improvement of the glasses themselves as amatter of little moment. They have vied with oneanother in mounting spectacles in the finest and mostflexible frames, and have produced articles finer andmore delicate than any which have before been made.They have, however, with this exception, been contentto follow in the steps of their forefathers, and have lostsight of the main object, in their desire to render theseuseful appurtenances to the sight as little visible andunsightly as possible. In the Foreign Section howpleasing a contrast is afforded by IIenki (France , Xo.262, p. 1189) who, viewing the subject in the properlight, has possessed himself of a thorough physiologicalknowledge of the eye, whether healthy or otherwise, andusing this knowledge as a basis for the exercise of hisskill as an optician, has succeeded in making greatadvances, and, by a skilful adaptation of the principles ofoptics, has been enabled to manufacture glasses, the fociof which are so arranged as to suit almost every peculiarityof vision. The glass, itself, is also of great purity, andremoves a fruitful source of the uneasiness and fatigueincident upon the use of spectacles.
Upon spectacles, as constructed by M. Henri, we haveno objection to report, combining as they do the work ofthe optician with a knowledge of optics; but we cannotconsider we are called upon to report upon spectacle-frames, or articles which have evidently been manu-factured and exhibited with a purely commercial view.
Rowley (Xo. 290, p. 439) has exhibited spectacles ofvarious kinds, chiefly remarkable for their durability ofmounting, both as regards material and construction,some being of no greater weight than 11 grains; thewhole weight, including glasses, not amounting to morethan 2 pennyweights. The steel frames of these lastresemble hair lines, and are imperceptible at no greatdistance.
Weaber (Xo. 279, p. 438) has exhibited several pairsof spectacles, many of them distinguished by a mountingof extreme lightness; also a steel hand frame, to beadjusted before the eyes, without pressing upon the nose.
Braithwaite (Xo. 233, p. 438) lias exhibited severalventilating eye-shades, designed to allow a current of airto circulate freely between the shade and the wearer, andthus to obviate the collection of heated air in the neigh-bourhood of the eyes.
Chadburn Brothers (No. 259, p. 436) lias exhibitedseveral pairs of clastic steel-framed spectacles, designedto combine lightness witli durability, and spectacles forvarious purposes. These, as well as everything exhibitedby Messrs. Chadburn, are remarkable for extreme cheap-ness, and in this respect they deserve Honourable Mention.
Bayley (Xo. 273, p. 438) has exhibited various spec-tacles, in mountings of gold and silver.
IIyams (No. 278, p. 438) exhibits a solid piece of glassof a conical shape, or rather of the form of a frustrum ofa cone, ground at the base or larger end to a convexsurface, and at the smaller end to a concave surface,intended for opera-glasses.
Dixey (Xo. 271, p. 43S) has exhibited a variety ofspectacles, some of them remarkable for their lightness,a variety of eye-glasses, and several binocular opera-glasses.
Clark (Xo. 276, p. 438) has exhibited spectaclesadapted for use, if required, as an opera-glass.
Elliott and Sons (Xo. 320, pp. 443, 444) exhibitspecimens of blue steel and gold spectacles of a verylight and flexible kind; also gold hand-spectacles, in-tended for use with one hand, and various specimens ofopera-glasses.
IIorne, Thorntiiwaite, and Wood (No. 220, p. 434),exhibit Smee's optometer, for ascertaining the refractoryhumours of the eye, and the required focus of spectacleglasses.
Braiiam (Xo. 289, p. 439) has exhibited various kindsof spectacles.
Callaghan (Xo. 268, p. 437) a pair of steel spectacles.
Solomon (No. 288, p. 437) a pair of eye-protectors.
WmTEHorsE (No. 280, p. 43S) various spectacles; apair for sketching, mounted without a rim to preventobstructing the vision.
\eates (No. 332, p. 446), of Dublin, spectacles of theordinary kind.
Henri (France , Xo. 262, p. 1189) lias exhibited severalkinds of improved spectacles, for correcting the defects ofvision; those for rectifying obliquity of vision (ortho-strabique) are made of steel, bronzed, and furnished witha moveable diaphragm, which may be shifted eitherright or left at will. They are designed for the cure ofsquinting, either converging or diverging. Spectacles forboth requirements are exhibited.
M. Henri has also exhibited spectacles for preservingthe eye-sight (conserves gardes-vues) designed for theuse of persons suffering from weak eyes, ophthalmia, &c.,and particularly adapted for the use of those who workmuch at night by artificial light.
With the skill of the optician, M. Henri has combinedthe knowledge of the oculist, and great praise is due tohim for the improvements lie has made in spectaclesadapted to peculiar states of the eye ; he has the furthermerit of being the only exhibitor of such spectacles inthe Exhibition. The Jury considered him well worthyof Honourable Mention.
Poullot (France , No. 966, p. 1226) has exhibitedvarious spectacles in very fine and slender mountings.
As M. Poullot considers a great part of the incon-venience experienced in the use of spectacles to be due tothe weight of the mounting or frame-work, he has beeninduced to make various trials for its rectification, byendeavouring to combine stability with the least possibleweight. He first contrived a pair of spectacles mountedin steel frames, filled with lead; hut the steel proved tobe too soft and the lead too heavy. After various attemptshe completed several of tempered steel, and entirelywithout seam or solder, the weight of which did notexceed a quarter of an ounce—a weight in itself insufficientto cause inconvenience to the wearer. The exceedinglightness and comparative elegance of these glasses isdesigned to remove the prejudice existing against spectaclesin general, owing to the reason before mentioned.
M. Poullot considers that he has made spectacles whichalways preserve the visual ray in the centre of the glass;he has also exhibited metallic woven spectacles for thefree admission of air to the eyes, which subdue the lightand serve as a screen against dust, insects, &c., or anyextraneous substance which might be injurious to theeye.
Lebrun (France , No. 298, p. 1191), exhibits manyvery cheap spectacles and opera-glasses.
Prudent (France , Xo. 1412, p. 1243) exhibits' a finecollection of opera-glasses, some of which have largeobject-glasses.
Buron (France , No. 443, p. 1199) has exhibited anumber of opera-glasses, both single and double, of whichthe mountings are of various materials, such as enamel,ivory, tortoiseshell, &c.
Busch (Prussia, Xo. 89, p. 1053) exhibits variousspectacles, differently mounted; single and double opera-glasses, lenses, See.
Latinie (Belgium , No. 1S4, p. 1157) has exhibitedvarious pairs of spectacles.
Bagen (France , Xo. 25, p. 1172) spectacle glasses.
Plagniol (France , Xo. 1679, p. 1257) spectacles ofvarious kinds.
Pick (Russia, No. 170, p. 1372) exhibits a pair ofspectacles.
Dissolving Views Apparatus.
AnHAiiAMaiid Co. (Xo. 263, p. 436) exhibit a trinoptricprismatic lantern. The three lanterns are illuminated hva small circular wick, through tiie centre of which a tubepasses for the purpose of supplying oxygen gas, by whichmeans an intense light is obtained. A disc of 25 feet foreach tube may he obtained, and each can he darkened toany extent, without any shadow on the picture. Thethree discs, by means of the prisms, can be throwntogether, or they can be placed at various distances onthe screen, forming one panoramic picture.
Abraham and Co. also exhibit a dioptric prismaticlantern, with two discs, which can be used as a dissolvingapparatus.
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