SCIOPTICON MANUAL. 151 



CHAPTEE XII. 



Sit* fim* f iflftt 



INTRODUCTION. 



THE Lime Light in an improved form having been 

 introduced into the Sciopticon, it becomes -expedient to 

 append to the Sciopticon Manual a description of the 

 apparatus and directions for its use. 



FLAME ILLUMINATION. 



We have in the Sciopticon oil lamp arrangement the 

 largest amount of ordinary flame illumination that can, 

 to advantage, be brought to bear upon the screen through 

 the objective lens, and as bright as air with its twenty 

 per cent, of oxygen will make it. 



Brightening the two flames by an inner supply of 

 oxygen gas, after the manner of the Bude light, heats 

 the wick tubes to an unsafe degree, and consumes too 

 much oxygen as compared with the efficiency of the 

 illumination. 



Some solid matter, of which quick-lime seems to be 

 the best and cheapest for the purpose, is more luminous 

 in an intense heat, than simply the particles of burn- 

 ing carbon floating off in flame. 



VARIETIES IN LIME LIGHT. 



Every lime light alike has lime and a jet of oxygen 

 gas; but a variety arises from the different conditions 

 of the hydrogen employed. With alcohol vapor, it is 

 commonly called the oxy-calcium ; with house gas led 



