Apparatus for ascertaining the Sensitiveness of Safety-lamps. 87 



Dieterici (Fr.) Alfarabl's Philosophische 



Leiden 1892. 

 Fayrer (Sir J.), F.R.S 



Abhandlungen. 8vo. 



The Author. 



On Serpent-worship and on the Venomous 



Snakes of India. 8vo. London. The Author. 



Hehir (P.) Microscopical Observations on the Hsematozoon of 



Malaria. 4to. Madras [1891]. The Author. 



Ricco (A.) Terremoti Sollevamento ed Eruzione Sottomarina a 



Pantelleria. 4to. Boma 1892. The Author. 



Wolf (R.) Astronomische Mittheilungen. No. 79. 8vo. [Zurich] 



1892. The Author. 



Bronze Medallion, 7 inches diameter, cast in honour of Professor 

 Rudolph Virchow, For. Mem. R.S. 



Virchow Testimonial Committee, Berlin. 



March 31, 1892. 



Mr. JOHN EVANS, D.C.L., LL.D., Treasurer and Vice-President, 



in the Chair. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The following Papers were read : — 



I. " x4.ii Improved Apparatus for ascertaining the Sensitiveness 

 of Safety-lamps when used for Gas-testing." By Frank 

 Clowes, D.Sc. (Lond.), Professor of Chemistry, University 

 College, Nottingham. Communicated by Professor ARM- 

 STRONG, F.R.S. Received March 24, 1892. 



An apparatus devised for the purpose of testing the sensitiveness 

 of different forms of miners' safety-lamps, when they are employed 

 for detecting and measuring low percentages of firedamp, has been 

 already described in the 'Roy. Soc. Proc.' (vol. 50, 1891, p. 122). 



The section of the apparatus (fig. V) shows that the apparatus 

 consists of a large cubical wooden box or chamber, into the upper 

 part of which the requisite measured volume of methane or firedamp 

 can be introduced, the complete admixture of this gas with the air 

 of the chamber being then secured by swinging up and down a broad 

 wooden flap, the area of which is nearly equal to the square section 

 of the chamber. 



