Manchester Memoirs, Vol xlii. ( 1 898), No. 7, 5 



Glass tubes were obtained of a strength such that they 

 withstood the pressure of the explosion wave travelling 

 one way, but broke when two waves came into collision in 

 the tube. The method depends on the principle that the 

 glass will respond to a pressure exerted on its sides, no 

 matter how short the time for which it is applied. 



In our experiments the same form of lead Y-piece 

 was used, save that special care was taken to ensure 

 absence of ridges at the junctions, by using brass caps 

 with flat ends in place of the rounded lead caps, and thus 

 having the glass tube fitting flush against the head of the 

 cap. The junctions were also made rigid with Faraday's 

 cement. With these junctions no retardation of the 

 explosion wave was found to occur. 



One limb of the Y-piece was so supplied with taps 

 that the apparatus could be filled with the explosive mix- 

 ture, and the flame made to travel down one or both limbs. 

 The explosion tube was fitted between the arms of the Y; 

 these being of equal length, the two explosions, when 

 desired, could be made to meet in the middle of the tube 

 to be tested. 



The miixture used was cyanogen gas mixed with its 

 own volume of oxygen. This is a mixture which under- 

 goes a simple reaction, and one unaccompanied by any 

 noticeable dissociation. 



Jena glass was used ; pieces of uniform bore and 

 thickness being chosen about 24 in. long ; 6 in. were 

 cut off from this to be tested hydraulically, the remaining 

 18 in. being used in the experiment itself The external 

 diameter was | in., and the thickness of the walls varied 

 from iV in- to i\ in. in different experiments. 



Among many attempts, four cases were noticed of 

 tubing which stood the explosion one way but which 

 broke on collision of two waves. Moreover, repeated 

 explosions were often made in such a tube one way, 



