OPTICAL INSTRUMENTS. 



165 



Goggles (Fig-. 653) are used 

 by persons having weak eyes, 

 in riding, diiving, or walking, as 

 a protection against the wind, 

 dust, light of the sun, or large 

 surfaces of water, snow, <fec. 

 They consist of glasses, white or 

 shaded, usually with plain sur- 

 faces, set in silver plated, or 

 black horn rims, and mounted 

 in leather at a proper distance 

 to be supported before the eyes 

 by strings passing round the 

 head. 



Price, 7octs. and $1.00. 



Wire Gauze Goggles, or Eye 

 Protectors. These are an excel- 

 lent protector for the eyes, and 

 are a great improvement on the 

 ordinary goggles, preventing the 

 heating of the eye by the con- 

 tact of the leather mounting in 

 the old kind, and allowing the 

 evaporation from the surface of 

 the eye to pass off unobstructed, 

 and as a shade to the eye, will 

 be found serviceable and agree- 

 able. They consist of an oval 

 shaped frame of wire, formed to 

 fit closely around the eye, hav- 

 ing caps of fine iron wire gauze, 

 covered with a dull varnish, of 

 sufficient size and convexity to 

 allow the eye-lashes to move 

 freely and unobstructed therein, 

 and supported by strings pass- 

 ing round the head. The effect 

 on the eye being about the same 

 as having a thick veil before it, 



