THE BOOK OF THE LANTERN. 



51 



is allowed to impinge upon it; it should be so adjusted 

 that the gas just escapes touching it while passing through 

 its flame. This form of lamp is sometimes fitted with a 

 wick of asbestos, which well resists the greatest heat that 

 can be brought against it. The oxycalcium lamp is valu- 

 able where no hydrogen gas can be obtained, and, while 

 far more powerful than a mineral oil flame, can hardly be 

 considered sufficiently powerful for use in a public lecture 

 hall. It is used in many of the hospitals in conjunction 

 with a simple form of lantern for throwing light upon 

 patients during certain operations. 



Before I reached the mature age of 

 twelve I had made oxygen gas by 

 nearly every available method, and had 

 used in this work sundry blacking 

 bottles, ginger-beer bottles, gun-barrels, 

 and gas-pipes, employing as gas-bags 

 disagreeable bladders fresh from the 

 butcher's. It is a wonder to me that 

 I was never blown skywards, but 

 blown-up in a figurative sense I often 

 was. It is now my turn to assume the 

 position of "stern parent," but in doing 

 so I soften towards the juvenile ex- 

 perimenter in memory of my own 

 misdeeds. Perhaps a description of 

 my first lime-light jet, made at 

 the cost of a few pence, of two FlG - 21 - 



gasfitters' blowpipes, will answer the purpose better than 

 anything else, of demonstrating the principle of the ordi- 



E2 



