44 LENSES, ETC. 



LENSES, &c. 



No. 



991 Fig. 686, plane glass, If diameter, - $ 0.12 



992 Fig. 687, double convex lens, " 0.38 



993 Fig. 688, double concave " " 38cts. to 0.62 



994 Fig. 689, plano-convex " " 50cts. to 0.62 



995 Fig. 690, plano-concave " " 50cts. to 0.62 



996 Fig. 691, meniscus " " - 0.50 



997 Set of lenses for showing their form and pro- 



perties ; consisting of double convex, double 

 concave, plano-convex, plano-concave, me- 

 niscus or concave-convex, and plain glass, 



all with ground edges, 1 f inch diameter, - 1.50 



Set of four first, 2 inches diameter, - - 3.50 



3 - 6.00 



998 Cosmorama lenses, convex, 7 inch diameter, 2.50 



999 " "6 inch " 1.75 



1000 " " 5 inch " 1.25 



1001 " " 4 inch " 1.00 



1002 " " 3 inch " 0.75 



1003 Magic lantern lenses, the pair, 2 inch, 1.25 



1004 " " 21 inch, 1.75 



1005 " " 3 inch, 4.00 



1006 " " 34- inch, 5.50 



1007 " " 4~ inch, 6.50 



1008 Microscope lenses, double convex, one inch 



focus and upwards, f inch diameter, 0.38 



1009 Microscope lenses, double convex, half inch 



focus, 50cts. ; quarter inch focus, 63cts. ; 



one eighth inch focus, - 0.88 



1010 Microscope lenses, plano-convex, one inch, 



SOcts. ; three quarter inch, 63cts ; half- 

 inch, 75cts. ; quarter inch, - - 0.88 



1011 Microscope lenses, diameter, l\ inches, 3 Sets, to 1.00 



1012 Telescope lenses, for eye-glasses, 3 Sets, to 0.50 



1013 " for object, 25cts. to 1.00 



1014 " " superior, 6 ft. focus, 1.25 



1015 " concave, for Gregorian eye- 



glass, - 3 Sets, to 0.50 



1016 " achromatic, 18 inch, 2.50 



to 42 inch, - - 25.00 



