THE BOOK OF THE LANTERN. 



37 



The mixture having been made, enough of it must be 

 placed in the retort to give the amount of gas which we 

 require. It will be found that if we allow one pound of 

 chlorate to every 4 feet of gas, it will be about right. 

 Roughly speaking, a bag of 8 feet capacity, a very useful 

 size, will take 2J Ib. of the mixture, and it is better to 

 waste a little chlorate than to have a bag which is not 

 quite full. Having charged the retort with the mixture, 

 we can screw on the delivery branch, taking care to insert 

 a washer of leather or asbestos cloth, to prevent any escape 

 of gas between branch and retort. 



In using a new retort, it is always well to blow 

 into it while the branch is fixed in position, so as to be 

 quite sure that there is no leak in the joints which has 

 escaped the maker's attention. Should a 

 leak be discovered, a little white lead will 

 remedy it for the time being. The retort 

 may now be placed on the gas-stove, while 

 its branch rests upon a chair or other 

 support. A tube at least 4 feet long, and 

 of a diameter agreeing with that of the 

 branch of the retort, should be drawn 

 over that branch for about 2 inches. The 

 other end of this tube is to be connected 

 with the wash-bottle. 



The kind of wash bottle which I 

 use, and which I can recommend very 

 highly, is also made by Oakley & Co. Fl . 17. 



of Bermondsey (fig. 17). It is of half a gallon 

 capacity, and is in reality a glass "Winchester quart" 



