332 FRAGMENTS OF SCIENCE. 



the sensitive flame into violent agitation. Here we 

 had imitated the aerial echoes heard when standing 

 behind the syren-trumpet at the South Foreland. The 

 experiment is extremely simple, and in the highest 

 degree impressive. 



The explosive rapidity of dynamite marks it as a 

 substance specially suitable for the production of sound. 

 At the suggestion of Professor Dewar, Mr. McRoberts 

 has carried out a series of experiments on dynamite, 

 with extremely promising results. Immediately after 

 the delivery of the foregoing lecture I was informed 

 that Mr. Brock proposed the employment of dynamite 

 in the Collinson rocket. 



