116 



REPORT — 1878. 



This table shows that it is easy, with properly adjusted batwing 

 burners, to obtain, with a consumption of from 3 to 5 cubic feet per hour, 

 at least the full effect of illumination exhibited in the standard mode 

 of testing already referred to ; and that even with a consumption of 

 2 cubic feet a very favourable result may be obtained. In no case is the 

 loss of light with batwing burners so great as with badly arranged union 



jets. 



Many other descriptions of improved batwings have been constructed, 

 some of which have been tested. The " Clegg " batwing, manufactured 

 by Sugo-, has a steatite top and a conical brass body closed at the bottom, 

 and with a slit cut in it with a fine saw. The respective sizes of the 

 slits above and below determine the consumption of gas and the pressure 

 at the point of ignition. In Silber's batwing, made by the Silber Light 

 Company, one burner is placed above another, both being of steatite, the 

 slitcf the lower one being much smaller than that of the upper, and con- 



