Application of the Galvanoscope. 



141 



Art. XX. — Application of the Galvanoscope to detect the Fail- 

 ure of Water in Steam Boilers ; by Charles G. Page, M. D., 

 Washington, D. 0. 



The prevention of accidents by the explosion of steam boilers, 

 has become to us a subject of vast moment ; and since its legis- 

 lation has been attempted, a multitude of plans have been devi- 

 sed, which should give warning of the approach of danger by 

 audible or visible indications of a deficit of water in the boiler. 

 No one of the plans so far proposed can be regarded as infallible, 

 and should even an unexceptionable monitor of danger be ob- 

 tained, it would utterly fail of its purpose, if we could not rely 

 upon the prompt and faithful co-operation of skillful engineers. 

 Nothing can be imagined more simple than the plan adopted by 

 the French, and English,* to show the level of the water in their 

 boilers. A stout, curved glass tube is connected with the inte- 

 rior of the boiler above and below the water, and shows plainly 

 at all times the level of the water in the boiler. It is not difficult 

 to understand why this simple invention has not received mer- 

 ited attention in this country, in some portions of which espe- 

 cially, the invariable rule has been to keep danger out of sight. 

 The plan I am about to propose, should it prove feasible, will 

 present a feature possessed by no other. As it will indicate the 

 state of things in the boilers with as much certainty to the pas- 

 sengers in the cabin as to the engineer in his room. The pro- 

 posal is to make the galvanic action of the water upon a pair of 

 plates or single plate, operate upon the needle of a galvanoscope, 

 and the cessation of this operation an index of the failure of its 

 cause. 



In the above figure, a represents a vertical middle section of 

 a steam boiler ; 6, a thick plate of zinc perforated with numerous 

 holes just under the surface of the water. This plate must be 



* E. g. in the Royal William, Atlantic Steamer, and in some steam boats on the 

 Delaware. 



