ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



641 



Oberhaeuser in Paris, when associated with M. Trecourt, about 1830. 

 The model is based on the " Drum " Microscope, the first form of 

 which was produced in 1742, by Benjamin Martin in his " Pocket 



Fig. 79. 



Reflecting Microscope." It was afterwards copied with modifications 

 and improvements by Frauenhofer (1811), and many other makers, and 

 has survived to the present day in the cheap form of school Microscopes. 



