BENJ. PIKE'S, JR., PRICE CATALOGUE. 47 

 No. 



1068 Fig. 706, camera lucida^ - - - $8 to $12.00 



1069 Fig. 707, graphic mirror, - $10 to 12.00 



1070 Fig. 708, polemoscope, - - 5.00 



1071 Multiplying glass, - 50 cts. to 3.00 



1072 Fig. 709, Claude Lorraine glass, with four to 



six glasses, - - $1.50 to 3.00 



1073 Claude black glass mirrors, ... 2.50 



POLARIZATION OF LIGHT. 



1074 Fig. 711, prism for double refraction, $2.50, 



$4, and 5.00 



1075 Nichol's prism, .... 5.00 



1076 Tourmaline plates, - $2 to 6.00 



1077 Fig. 712, tourmaline polariscope, - $4 and 4.50 



1078 Variety of crystals set in cork frames between 



glass plates, for preservation, used with the 

 polariscope, each - - 0.75 



1079 Figs. 717 to 722,selenite designs, in polished 



mahogany frames, - - each $2.50 to 4.00 



1080 Fig. 723, Biot's reflecting polariscope, - 36.00 



1081 Fig. 724, polariscope, with six selenite de- 



signs in case, - - 25.00 



1082 Fig. 725, brass frame, for showing the tran- 



sient polarizing structure communicated by 

 pressure to a piece of annealed glass, - 3.50 



1083 Fig. 728, brass frame for showing the same 



by the unequal application of heat, - 2.00 



1084 Fig. 726, brass frame and glass plate for 



showing the same by bending, - - 5.00 



1085 Fig. 729, five unannealed glasses for show- 



ing the tints of polarized light, - - 8.00 



1086 Ten ditto, - - - 15.00 



1087 Two rectangular pieces of unannealed glass, 



which may be placed over or across each 

 other, for showing the tints of polarized 

 light, ... . 2.50 



1088 Savarre polarizing eye-piece, - - 6.00 



