z8o 



OPTICAL PROJECTION 



'luminous cascade,' depending on the fact that if we can send 

 a nearly parallel beam of light ' end on ' into a stream of 



... water as it issues 



II . from a horizontal 



Jytr.v.tj orifice, it is reflected 

 "" from side to side, 

 except as regards 

 small dust particles, 

 which apparently 

 convert the stream 

 into one of living 

 fire. In front of the 

 open nozzle some 



sort of close vessel must be arranged, transparent at the back 

 and with the issuing orifice in front, while there must be 



FIG. 147 



FIG. 148. Cascade 



another orifice by which to keep the vessel supplied with water 



