1 78 Mr. Snow Harris on Lightning Conductors, 



I was called upon, for instance, to show what had been the 

 general laws of the action of lightning on ship-board; that the 

 connexion of my conductors with the sea through the metallic 

 masses in the hull was in no way detrimental to' their action, 

 or liable to objection; that, in short, electrical discharges might 

 find their way and become as safely dispersed in the sea by 

 the metallic bolts driven through the keel and keelson, and 

 other parts of the vessel, as by a chain in the rigging. 



I was further called upon to show, so far as possible, how 

 a system, such as I proposed, would operate in this way under 

 various positions of the masts, and that the circumstance 

 of their motion upon each other would in no way interfere 

 with the action of the conductor. In order to meet the views 

 of the officers of the Board, I naturally enough resorted to 

 such practical illustrations as were within my reach. By way 

 of showing the operation of my conductors through the bolts 

 in the hull, strong charges from twenty-five square feet of 

 coated glass were passed over a vessel's mast fitted with the 

 conductors and floating in the sea, the negative side of the 

 battery being connected with an interrupted circuit passing 

 over a small gun placed in a boat (in some instances) forty 

 fathoms from the vessel. Percussion powder was placed 

 over the joints of the conductor on the mast, and in an in- 

 terrupted circuit at the mast head. The sliding masts were 

 placed in various positions, and occasionally were put 

 in motion at the time of the experiment; but in all cases 

 at the instant of completing the circuit, the whole charge, 

 equivalent to fuse fifteen feet of small iron wire, passed freely 

 through the conductor and the sea in all positions of the masts 

 without igniting the powder placed over the joints, but firing 

 the powder at the mast-head, and the gun, instantaneously, 

 thereby showing that the charge had reached from the mast 

 head to the water. 



Any one will, I think, perceive that these experiments illus- 

 trated, so far as they went, the points in question, viz. 

 1st. The operation of the conductor through the hull. 

 2nd. Its perfect continuity on the masts. 

 3rd. Its complete operation under every possible position, 

 &c. of the masts. 



4th. The reception of the charge by the sea. 

 Now Mr. Sturgeon fairly shuts his eyes to the unpretend- 

 ing nature and object of these experiments, and perverting 

 their meaning, tells his readers that they prove nothing pecu- 

 liar to my system, and serve only to show that copper is a 

 conductor of electricity, and that detonating powder can be 



