72 
ELEMENTARY CHEMICAL MICROSCOPY 
the instrument to use in almost any position and the speed with 
which large areas may be studied, all combine to render this 
type of instrument indispensable in the industries. 
One of the most satisfactory of the models of this instru¬ 
ment ^ is illustrated in Figs. 30, 31. The various figures show- 
Fig. 30. Spencer Lens Co. Greenough-Type Binocular Microscope; Bausch & 
, Lomb Lamp; Starrett Clamps; arranged for the removal of tiny fragments 
for microscopic qualitative analysis. 
ing the microscope in different positions and with different 
arrangements as to stages and objects are sufficiently clear 
that they require no lengthy descriptions of the ways in 
which the instrument may be used. The microscope, having 
a “ flexible ” pillar, may also be used in a horizontal position. 
A few words are, however, necessary relating to the construc¬ 
tion and adjustment of the instrument. 
1 Made by Spencer Lens Co., Buffalo, N. Y. 
