Adams's " Variable" Microscope. By Edward M.Nelson. 181 



which is now in our collection, is made precisely upon that plan, 

 and is the earliest Microscope of this typo in our collection, as its 

 date is 1775. 



We are therefore justified in calling the Variable, fig. 27, 

 although the third in seniority, the most important of the three. 



It has always been an interesting problem to discover the 



Fig. 28.— Adams, 1785. 



identity of this anonymous " noble person," and now I think I am 

 able to give you his name ; not, of course, with the evidence of an 

 affidavit, but with a very high degree of probability. 



First, the fact that he was a noble person narrows down the 

 list from which we have to select a name. At that date there was 

 one man who, if he was not the anonymous author of this 

 important instrument, fits the circumstances of the case in all 

 particulars. He was not a peer, but the son of the brother of a 



