OPTICAL INSTRUMENTS. 157 



best mounting for them being fine steel, being the lightest, 

 and attaching firmly to the head. 



Price, of best quality, - |5.00. 



" 2d " $4.50. 



" commoner, - $2.50. 



" with ordinary size glasses, $1.50. 



Spectacle Cases. (Fig. 639.) The cut in the previous 

 page represents the usual style of the morocco spectacle case. 

 They are also made soft, with one or both ends open, and 

 occupying but little space in the pocket, but not protecting 

 the spectacles, as the one represented in the cut. They are 

 made of a variety of colors, but most usually red and dark 

 blue. Price, 12cts. 



Single Eye Glasses. Eye glasses are frequently used 

 instead of spectacles, being less formal and more convenient 

 for occasional purposes, as in reading a letter, viewing any 

 object fcr a moment, either near or distant as the case 

 may require. They are mounted in a variety of setting, 

 black horn, tortoise-shell, fine steel, silver, and gold (those 

 in tortoise-shell being the most used), and are worn sus- 

 pended from a guard around the neck. 



Round Shell Eye- Glass. (Fig. 640.) 



Fig. 610. 



Price, round shell eye-glass, $1.00. 

 " black horn eye-glass, 63 cts. 

 VOL. ir. 14 



