1038 SUMMARY or CURRENT RESEARCHES RELATING TO 



the speaker to be the critical point of no variation of temperature when 

 there was an equilibrium between the temperature of the bars of metal, of 

 the surrounding air, and of the thermometer employed. As a result of 

 observations extending from December, 1886, to July, 1887, the conclusion 

 was reached, first ; ' That the relative coefficients of expansion of these 

 metals are really constant for ordinary temperatures ; and second, that the 

 values of the absolute coefficients have not changed since 1881.' " * 



Fasoldt's Rulings.t — Mr. C. Fasoldt writes as follows : — " A gentleman 

 interested in microscopy lately called my attention to an item in the report 

 of the Microscopical Society of Washington, D.C., in the April number 

 of the ' American Monthly Microscopical Journal,' p, 77 : ' Dr. Schaeffer 

 asked if any of the Society had seen Fasoldt's ruling on glass. Prof. 

 Seaman said Fasoldt had done some fine work, but the finest was that done 

 by Prof. Eogers,' &c. 



I was not aware that I was recognized as an amateur in mechanics, 

 and that I imposed on the world with inferior products ; neither has a 

 commission of any exhibition ever rendered such a verdict. Contrary to 

 that, in World, International, and State Exhibitions I was always recognized 

 as master of the masters, which is shown by the following first-class 



Prize Medal of Honour and Diploma of Merit awarded at the Cen- 

 tennial Exposition of 1876. Also First Prize Medal and Diploma, 

 International Industrial Exhibition, Bufialo, N.Y. Three First Prize 

 Medals, Utica Mechanics' Association. First Premium Medal, Syracuse 

 Mechanics' Association. Silver Medal and Certificate of Highest Merit of 

 New York State. 



Eegarding the sentence that I do not publish my method of ruling, I do 

 not want to dictate to other persons what methods to use to accomplish a 

 certain work — in somewhat by showing and illustrating my machine — 

 neither do I want to contradict those who attempt to illustrate how work 

 is and should be done. I claim that everybody has the privilege to 

 construct and make their own Microscope, measuring and illuminating 

 apparatus, ruling machine, and machinery to make those and all other 

 devices that anybody wished to make for private or general public use, as 

 I have done. 



As it is proper for a man to uphold and prove what he has said, or either 

 retract such quotation, I would ask Prof. Seaman to send the following 

 rulings made by Prof. Eogers. All test-plates should be ruled in bands, 

 beginning with and running up every 10,000 to the denomination as given 

 below. 



1 plate ruled up to 200,000, or 250,000 lines per inch 



1 „ „ » 120,000 



1 „ „ „ 6,000 



3 stage mic. ruled 1, 10, 100, 1000 per inch. 



3 stage mic. ruled 100, 1000, 5000, 10,000 lines per inch. 

 When I will appoint a committee of four to measure and resolve them. 

 And the Professor can appoint his committee and do likewise with my 

 rulings. 



We have numerous times resolved 200,000 and over. I have the 

 facilities to do it with, and measuring likewise." 



* Cf. Amer. Mon. Micr. Joum., viii. (1887) pp. 196-7, for a criticism on this address, 

 so far as it defends the claim of microscopy to the title of a science. " We see no 

 advantage to be gained by naming a science which does not exist. In a truly scientific 

 sense there is no such thing as a science of microscopy as defined by Prof. Eogers." 



t Amer. Mon. Micr. Journ., viii. (1887) pp. 175-6. 



