156 



GENERAL SCIENCE 



illuminating purposes two classes of burners are in common 

 use. 



1. The fishtail burner causes the gas to separate out into a 



FIG. 125. Cotton, ramie, and 

 artificial silk are used for 

 manufacturing mantles. 



FIG. 126. Knitting. A thread of suitable 

 size is knit into a tubular fabric on a 

 machine modified from those used in 

 knitting underwear. Saturating. The 

 I lengths of knitted fabric are placed in 

 a suitable vessel and the so-called 

 ^lighting fluid is poured over them. 



FIG. 122. Monazite sand 

 obtained from Brazil, 

 Australia, and from this 

 country. 



FIGS. 123 and 124. Cerium and thorium 

 nitrates are obtained from sand, and the cloth 

 mantles are dipped into solutions made from 

 these chemicals. 



thin sheet so that enough air is brought in contact with the car- 

 bon to burn it, but not until it has been heated to a glowing tem- 

 perature. 



