120 



REPORT — 1878. 



These tests show that the cone, by increasing the draught, enables a 

 larger quantity of gas to be burned, an effect which could be obtained' 

 equally well by increasing the height of the chimney ; and the air tube of 

 the Silber burner also produces a similar effect, increasing at the same 

 time the heat and illuminating power of the flame and its stability. 

 Indeed, the Silber burner without cone and centre tube, and especially 

 when the latter is removed, gives so unsteady a flame that it is practically 

 useless for illumination, while, in its complete condition, it gives the 

 steadiest flame of any Argand yet constructed. 



A series of experiments were made in order to ascertain the relative 

 dimensions of the inlet and outlet of various burners. The npper steatite 

 portion of each burner was removed and fitted up in a little bit of appa- 

 ratus extemporised for the purpose, so that gas could be passed through the 

 boles, while the bottom portions were simply screwed on in the usual 

 manner, and the gas allowed to escape without lighting it. In all the 

 trials the pressure of the gas was maintained steadily at • 2 of an inch of 

 -water. The numbers represent cubic feet of gas per hour : — 



Sugg-Letheby 15-hole burner 



Sugg 24-hole standard London Argand 



Do . 36-hole older pattern 



Silber 24-hole 



Do. 40-hole 



These results show that the pressure of the gas is checked much more 

 efficiently at the bottom of the burner by Sugg's arrangement than by 

 that of Silber, and in fact the latter has usually attached to it a small 

 regulator adjustable by a screw, without which, and when regulated only 

 by a stopcock, a disagreeable hissing noise is produced by the passage of 

 the gas through the almost closed stopcock. 



The " Bee a Bengel," or Bengel Argand burner, used for gas testing in 

 Paris, has a porcelain top, with 30 rather small holes, a brass cone, and at 



