194 THE MICROSCOPE. [September, 



find such an instrument in the market, he asked Bausch & Lomb, 

 the well-known optical firm, to make one which would fulfil the 

 required conditions. After many trials the instrument was com- 

 pleted to his entire satisfaction. The instrument in question is 

 an eye-piece in which there is a fine spider web moved by means 

 of a precision screw. The difticulty in ordinary micrometers 

 consists in the lack of delicacy of movement of the springs which 

 press the micrometer plate against the end of the screw. This 

 difliculty Bausch & Lomb have averted. 



Professor Rogers read a second paper, on the " Use of the Mi- 

 croscope in the Workshop." The speaker stated that he had for 

 some years advocated a more extensive use of the microscope 

 in the ordinary operations of mechanical construction. His 

 paper was an enumeration of the different mechanical operations 

 in which he found the use of the microscope profitable. 



Thursday Afternoon. 



Papers were presented at to-day's meeting by Professor Kelli- 

 cott, Dr. Munn, G. W. Rafter, Dr. Mercer, M. L. Holbrook, 

 Professor E. H. Griffith, and Mr. Frank Zentmayer. 



Later in the afternoon the members and friends took cars at the 

 university for the Bausch & Lomb Optical Company's factory, 

 where the remainder of the afternoon was utilized in an inspec- 

 tion of the works. 



Thursday Evening — The Soiree. 



As at all previous meetings, the soiree was the notable feature 

 of the assemblv of microscopists. At 8 o'clock the microscopes 

 were all in place and the exhibit was in full progress. 



Most of the objects exhibited were of a popular nature rather 

 than of the most particular scientific interest. Among them were 

 exquisite histological specimens, diatoms, metals, disease growths, 

 tissues, forms of vegetable and animal life, bacteria, trichinae, 

 gold, hairs, teeth, crystal, &c. 



The exhibit lasted two hours, and the wonders of the micro- 

 scope seemed veritable miracles to some, who for the first time 

 peered through the tube. There were at least a hundred micro- 

 scopes, and every one of them was besieged by a line of eagerly 

 curious men and women. 



In one of the microscopes shown by Professor Griffith was a 

 bouquet of flowers. It was made of the scales of the butterfly 

 arranged with the most wonderful artistic skill in a space no 

 bigger than a pinhead. Another microscope revealed the Lord's 

 prayer through a pinhole. The exhibit which attracted the 

 largest share of attention and which, perhaps, was the most in- 

 structive was a series of nine microscopic objectives interspersed 

 with drawings showing the growth of the starfish at all stages. 



