CH. IV] MANAGEMENT OF THE LIME LIGHT 



N 



107 



FIG. 59. MIXED BURNER OR JET FOR THE LIME LIGHT. 

 (From the Catalogue of Williams Brown & Earle). 



H H The metal tube of the burner conveying the hydrogen to the mixing 

 chamber (M}. It should be painted red to correspond with the color of the 

 hydrogen cylinder of compressed gas. 



The metal tube conveying oxygen to the mixing chamber (M). It 

 should be painted black to correspond with the color of the oxygen cylinder of 

 compressed gas. 



M The common chamber into which open the oxygen and hydrogen tubes. 

 Here the gases mix before passing out through the nozzle (N). 



N The nozzle or outlet tube from the mixing chamber. It is at an inclina- 

 tion of about 40 to 45 degrees with the vertically standing lime face; and 

 when the burner is in action the nozzle and lime are about 3 mm. (J/gth in-) 

 apart. 



L The support and springs for holding the lime. 



5 The milled heads of the pinions by which the lime is rotated or raised and 

 lowered. The lime support slides back and forth on the supply tubes O and // 

 so that the lime may be withdrawn from or made to approach the tip of the 

 nozzle (N). 



open the stop-cock until the flair.e is from 8 to 15 cm. (3-6 in.) long. 

 Then turn on the oxygen slowly until the flame just commences to 

 hiss. After the lamp has been going some minutes the operator 

 can slightly increase or decrease the oxygen until the most brilliant 

 light is obtained. One must learn by experience. The flame will 

 become very small as the oxygen is turned on, and this small, 

 intensely hot flame heats a very small part of the lime, hence the 

 source of light is very small, something like the crater of the posi- 

 tive carbon in the direct current arc lamp. 



Caution. Always turn on the hydrogen first and light it before 

 turning on the oxygen. 



Never turn on the oxygen first, and never until the hydrogen 

 has been lighted, and then turn it on slowly. 



If both were turned on before lighting the hydrogen, there would 

 be a greater or less explosion. This might not be very dangerous, 



