108 



CONSTRUCTION OF THE MICROSCOPE. 



FiG. 27. 



the Naturalist ; and may be constructed at so trifling an expense, 

 to work with any objectives he already may possess, that a con- 

 siderable demand may be anticipated for it. 1 



37. We now pass to an entirely different class of instruments, 

 those of which the aim is, not simplicity but perfection ; not 

 the production of the best effect with limited means, but the at- 

 tainment of everything that the Microscope can accomplish, .with- 

 out regard to cost or complexity. This object has been certainly 

 carried out by the Opticians of our own country, much more com- 

 pletely than by those of the Continent ; and it seems but fair to- 

 wards the three principal London makers, by whose labors the 

 present admirable results have been attained, that the pattern 

 finally adopted by each should be here delineated and described. 

 Without any invidious preference, the first place may fairly be 



assigned to the Large 

 Compound Microscope 

 of Mr. Ross; not 

 only as being the 

 one which was first 

 brought (in all essen- 

 tial features at least) to 

 its present form, but 

 also because it is that 

 which contains the 

 greatest number of 

 provisions for investi- 

 gating objects in a 

 variety of different 

 modes. The general 

 plan of Mr. Ross's Mi- 

 croscope will be seen 

 to be essentially the 

 same with that which 

 has been followed by 

 Mr. Field in the simple 

 form of this instru- 

 ment first described 

 ( 31), as weH as by 

 many other makers ; 

 but it is carried out 

 with the greatest at- 

 tention to solidity of 

 construction, in those 

 parts especially which 



are most liable to tremor ; and we are informed by Mr. Eoss, 

 that every part has been tested by the "inverted pendulum" 



' This instrument has been made for Mr. Warington and for the Author by Mr. 

 Salmon, 100 Fenchurch Street ; who supplies it, on either plan, without objectives or 

 case, but with condenser and stage-forceps, for 3 guineas. 



