692 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



We found the mechanism as left by Andrew Eoss, and it has since 

 been applied to a stand by Mr. Anderson, who informs us that he 

 assisted in the original construction about fifty years ago. 



Fig. 82. 



Fig. 83. 



M'lntosh's Microscope-Attachment.* — Dr. L. D. M'Intosh devised 

 this apparatus for use with solar or artificial light for projecting or 

 photographing microscopic objects with oblique illumination, or pro- 

 jecting opaque objects, and before describing it he explains the con- 

 struction of his solar Microscope and stereopticon combination (fig. 84). 

 The optical parts can be used with either solar or artificial light, with 

 only slight changes. To use sunlight, there is a plane mirror M, 12 by 

 14 in., which turns on a vertical horizontal axis by means of spur-wheel 

 gears connected with rods E, E. The gears are supported by a bracket, 

 which is securely clamped to a perpendicular board F. On th*e front of 

 this board is an opening to receive the condensing lenp, which is 

 mounted in a brass tube C, with draw-tube. The draw-tube E has a 

 screw-thread to receive either the microscopic attachment K, for pro- 

 jecting microscopic objects, or a stereopticon lens for projecting photo- 

 graphic transparencies. By means of the thumb-wheels V, W, the 



* Proc. Amer. Soc. Micr., x. (1888) pp. 155-8 (4 figs.). 



