198 



BENJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. 



inches in diameter, set in polished mahogany frames, and 

 are represented in the polariscope, Fig. 712 ; some of the 

 designs represent five and six pointed stars, rosettes, tulips, 

 thistle, the flower forget-me-not, and a variety of others, 

 some having mottoes. A few representations are given in 

 Figs. 717 to 722 ; but to form any idea of their beauty 

 they must be seen in their beautiful coloring. 



Price, $2.50, $3.00, and $4.00, each. 



Fig. 723. 



BioCs Reflecting Polari- 

 scope. (Fig. 723.) Biot's 

 reflecting polariscope, as re- 

 presented in the cut, hav- 

 ing polarizing and analysing 

 plates with horizontal move- 

 ment, and graduated circle ; 

 movable stage for crystalline 

 plates, tourmaline cell, dou- 

 ble image or Nichol's prism, 

 plane mirror, and condens- 

 ing lens. The framework of 

 highly finished brass mount- 

 ed on a mahogany base, with 

 drawer for holding the smaT- 

 er parts. 



Price, $12.00. 



