THE PROJECTION MICROSCOPE 18 1 



any traces of his actual instrument, or any record of its per- 

 formance, or that it had ever come into use. This being so, 

 however, I had to begin de novo, and lost much time by 

 making my first experiments with diatoms. It was my friend 

 Mr. T. Curties, F.R.M.S., who guided me out of that unprofit- 

 able track, and gave me to understand that he should die 

 happy if he could only see upon a screen, bright and sharp, 

 ' the tongue of a blow-fly six feet long. That,' he said, ' is 

 what we want.' As I knew already that I could give him 

 more than double these dimensions easily, I was considerably 

 relieved ; and the instrument was shortly afterwards com- 

 pleted. It was first publicly exhibited at a meeting of the 

 Eoyal Microscopical Society on Nov. 12, 1884, and again at 

 the Quekett Club a few days later, to the entire satisfaction 

 of the many experienced microscopists present on both occa- 

 sions. 1 



I shall content myself here with describing the projection- 

 microscope as constructed by Messrs. Newton & Co. from my 

 own designs, notwithstanding that since its introduction I 

 have seen one or two others catalogued which are stated to 

 perform well. I do not question this, but there are many 

 reasons for the course here adopted. No such instruments 

 were produced till some time after that here described ; 2 none 

 have been demonstrated in the same public manner ; none 

 have come into nearly such general use or met with such in- 



1 See Journal, R. M. S., December 1884, p. 1006, and Journal 

 Quekett Mic. Club, March 1885, p. 118. 



2 One exception ought to be made, in fairness, respecting a German in- 

 strument. Particulars were published of a projection microscope designed by 

 Dr. Hugo Schroeder, before my instrument was exhibited, though not till after 

 it was completed. Dr. Schroeder's, which has been stated to perform excel- 

 lently, was therefore worked out in perfect independence of mine, as mine 

 was of his. With the exception of the concave parallelising lens presently 

 described, which has been generally used, and is mentioned by Kingsley, 

 there is, however, little in common in practical detail to the two instruments, 

 and the cost of Dr. Schroeder's, which is far more complicated, was stated to 

 be about 200Z. 



