no 



E. M. NELSON ON EVOLUTION OF THE MICROSCOPE. 



axis. In 1746 Adams adapted his microscope stand in a very 

 ingenious manner to this projection apparatus, thus forming the 

 earliest prototype of the projection and photographic instruments 

 of the present day. (Fig. 19.) 



Without anticipating the description of Adams' microscope, 

 it may be stated that the instrument is of a vertical non- 

 inclinable form with a folding tripod foot. The front leg of 

 the tripod has a circular aperature in it, through which the 

 conical nose of the illuminating portion of the projection apparatus 

 is inserted, the microscope being placed in a horizontal position. 

 Adams' solar projection microscope has been chosen as typical 

 of the whole series ; Cuff's, which is figured in the second edition 



Fig. 19. 



of Bilker on the Microscope (1743), has the illuminating portion 

 of the apparatus similar to Fig. 19, but the microscope part of 

 it is different. 



After occupying so much space over the year 1738, we will 

 pass on to the next year, when we meet with the first microscope 

 designed by that celebrated mathematician and inventor, Benjamin 

 Martin.* 



* Benjamin Martin was born at Worplesdon, in Surrey, in 1704, and 

 began life as a ploughboy ; afterwards {circa 173-4) he became a school- 

 master at Chichester ; subsequently {circa 1759) an optical instrument 

 maker at the Sign of the Visual Glasses and Hadley's Quadrant, 171, Fleet 

 Street. He was also an author, and published about thirty-nine works on 

 physical science, mathematics, optics, astronomy, etc. He died in 1782, 

 and in this year his son Joshua Lover Martin took out a patent for drawing 

 metal tubes. (See admirable account of B. Martin, by John Williams, 

 Trans. Mic. Soc. Land., Jan. and Oct. 1862, Vols. 2 and 3, New Ser., p. 31 

 and p. 1.) 



