NOTES AND MEMOEANDA. 



471 



also had certain defects which could be best overcome by adopting and 

 modifying a good English model. 



The great defects in most of the Microscopes built on the conti- 

 nental patterns consist in their fixed vertical position, the smalhiess of 

 tlieir stages, and, very commonly, in the absence of any means of 

 coarse adjustment, except by a sliding movement of the body or tube, 

 which, if working stifliy, is very inconvenient, while, if sliding easily, 

 it is apt to be shifted by a very slight toucli. 



The instrument now manufactured by Mr. Watsan is in most 

 respects quite equal in performance to Rosenbusch's, so far as the 

 mechanical a^ipliaucos and adjustments are concerned, and is, in point 

 of convenience, decidedly superior to the latter instrument. 



The general form of the instrument is sufficiently shown in the 

 accompanying woodcut. In the stand first made the milled head of 



