The National Microscopical Congress. 67 



come, the action of the Congress will be of considerable in- 

 terest. 



Dr. W. T. Belfield read the first paper, which is published on 

 page 37. 



Mr. C. M. Vorce described a method of measuring which he 

 had found convenient. It consisted of a series of scales prop- 

 erly divided, one for each objective, for use with the camera. 



Mr. Hitchcock read a paper entitled 



" A STANDARD MICROMETER." 



An abstract of this is found on page 47. 



Dr. R. H. Ward then followed with some extempore remarks 

 of great value, relating to the ruling of plates and the accu- 

 racy attainable in our standard divisions. These were of a 

 most interesting character, but unfortunately were not written 

 out. 



Prof. J. D. Hyatt then made a few remarks embracing an 

 account of his work on bee stings. 



The afternoon was occupied with an excursion on the "belt 

 line '■ railroad by invitation, and in the evening an exhibition 

 of instruments and objects was held which was well attended 

 by the citizens. 



On Saturday the business relating to permanent organiza- 

 tion was first attended to. with the results already stated. 



Prof. J. Edwards Smith spoke for a few minutes on 



•' THE PROGRESS OF MICROSCOPIC RULING." 



He stated that Prof. Rogers had ruled i2o.cxx3 lines to the 

 inch, which he (Prof. Smith) had succeeded in resolving by 

 reflected light. In reply to a question he answered, that by 

 transmitted light he was not able to resolve these lines. Prof. 

 Rogers believes he can make a band with 240.000 lines to the 

 inch. Remarks are superfluous on this. The band may be 

 made, but we much doubt if it will ever be seen. 



The following papers were read bv* title : 



" Ox THE coxsTRUCTiox OF OCULARS," by W. H. Seaman. 

 • A XEw AXALvziXG EYE-PIECE." by Prof. Wm. Lighton. 



" A XEW ARRAXGEMEXT FOR DARK FIELD ILLUMIXATIOX." by 



Prof. Wm. Lighton. 



"A XEW sECTiox CUTTER." by Dr. Carl Seiler. 



Mr. John Sidle described a new and ingenious self-centering 

 turn-table, devised bv himself. 



