Transactions . een the difference,in the ease of the illumination and the clearness and brilliancy ofthe picture. By their use, a large quantity of light is saved, sincethe correcting glass, instead of being at a considerable angle with theaxis of vision, and therefore in a position favorable to a largely in-creased loss of light through reflection from the surface of the glass,is nearly at right angles to it, by which all the light possible is mirror gives also ample light for the inverted image, and I nowuse it entirely for all methods of examination. The instrument is made with o
Transactions . een the difference,in the ease of the illumination and the clearness and brilliancy ofthe picture. By their use, a large quantity of light is saved, sincethe correcting glass, instead of being at a considerable angle with theaxis of vision, and therefore in a position favorable to a largely in-creased loss of light through reflection from the surface of the glass,is nearly at right angles to it, by which all the light possible is mirror gives also ample light for the inverted image, and I nowuse it entirely for all methods of examination. The instrument is made with or without a cover for the posteriorsurface of the glasses. As a matter of fact, the glasses can be kept 494 cleaner when the posterior surface is not covered than when it is,provided that, as in the present case, they are protected by a rim. Fig. 2 represents the same instrument with a different method ofnotation, consisting of two concentric rows of figures, the outer rowbeing the plus and the inner the
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectophthalmology, bookye
