352 Apparatus for Rock Blasting* 



solid and permanent effect, upon the human mind, than the impres- 

 sion of a splendid scene. To return, however, to our . immediate 

 subject and its connexion with the cause of human knowledge: 

 we may well regret that, with so much to be known apparently with- 

 in our reach, so little that is definite should be, as yet, disclosed- 

 Yet the success — partial though it be — which has rewarded the few 

 investigations which have been perseveringly made, yields an induce- 

 ment to more systematic effort; and we trust that individuals who 

 have the time at command, will deem it, even now, a labor well be- 

 stowed, to rescue from oblivion any one well ascertained fact respec- 

 ting these wonderful phenomena. 



Art. IX. — Communications by Dr. Hare. 



1. Description of a process, and an apparatus, for Blasting Rocks, 



by means of Galvanic Ignition. 



Remark. — That portion of this article which precedes the first cut, 

 was published in this Journal (Vol. xxi. p. 139.) — but, it is thought 

 best to republish it now in connexion with the additional illustrations, 

 rather than give the reader the trouble of looking into the separate 



volumes. — Ed. 



I have observed various accounts in the newspapers of workmen 

 killed or dreadfully lacerated, by the blasting of rocks. 



This, and many like occurrences will, I presume, create sufficient 

 interest in the following communication, to justify its appearance in 

 the American Journal of Science. 



I have ascertained that by a new application of galvanism, rocks 

 may be riven w T ith less danger than that which attends the firing of a 

 pistol. I was induced to attempt this improvement in consequence of 

 an application by a patentee (Mr. Moses Shaw,) for assistance in per- 

 fecting his patented mode of blasting rocks, by an electrical discharge 

 from a Leyden jar. 



In a letter dated June 1st, 1831, he says, "I have been engaged 

 in blasting rocks by means of a fulminating powder, introduced into 

 several cavities, and ignited in all of them simultaneously, by a spark 

 from an electrical machine, by which means masses of a much larger 

 size, and of a much more suitable shape, for any object in view, may 



