4(y2 Proceedings of the Society of Arts. 



C. The Report of the Committee on Mr Hunter of Thurston's new 

 Scale for the Thermometer w.'is read and approved of. Dr Fyfe, Con- 

 vener. 



7. Mr Sang obtained leave to print the remaining" part of his Essay on 

 Life Assurance, which is to be read at next meeting. 



I. The following Candidates were admitted as Ordinary 

 Members, viz. : — 



1. John G. M. Burt, M. D., 8 Bank Street ; 2. Robert Cowan, Esq. 

 W.S., Great King Street ; 3. Hugo Reid, Esq., lecturer on Chemistry, 

 24 Nicolson Street. 



II. The Experimental Committee reported the election of 

 their Office-bearers for 1840. Mr Ponton, Convener. 



III. A letter from the Secretaries of the intended Exhibi- 

 tion of Arts and Manufactm'es at Newcastle-on-Tyne was read. 



The Secretary and Curator were appointed a Committee to 

 answer the letter, and with power to send any models, &C.3 

 which the Newcastle Committee may desire. 



Wth March, 1 840. Sir John Graham Dalyell, President, in 

 the Chair. The following communications were made : — 



1. On the Comparative Illuminating Power of different kinds of Gas 

 Burners. By Andrew Fyfe, M.D., F.R.S.E., M.S.A. (694.) In trying 

 the comparative illuminating powers of different Gas-Burners, Dr F3 fc 

 stated that he took a single Jet-burner, burning with a flame of 5 inches 

 in length as the standard, in which case he had it so adjusted as to burn 

 exactly one foot per hour. Assuming the light given by this burner, as 

 thus used, to be as - - - - 100 



The light given by a Fish-tail for an equal consumpt 



of gas is - - - ^ 140 



By a Bat- wing, about - - - » 164 



By an Argand (24 holes) - - - 180 



Accordingly, for equal consumpts of gas, the additional light given, 

 over and above that afforded by a jet, is, by the Fish-tail 40, by the Br.t- 

 wing upwards of 60, and by an Argand 80 per cent. For this purpose, 

 however, it is necessary to use the Fish-tail and Bat-wing, burning with 

 their full supply of gas, and to have the Argand with a flame of about 

 three inches. On increasing the number of holes in the Argand, though 

 the quantity of gas consumed becomes greater, the comparative illumina- 

 ting power is not augmented ; the increase in light being merely proj)or- 

 tionate to the enlarged expenditure. From the numerous experiments 

 ^ich he had performed, Dr Fyfe stated that he had come to the conclu- 

 sion, that the Argand is by far the most economical method of consuming 



