§3'2 Electrical Conductors for Ships. 



jured, are very obvious. This species of conductor is therefore 

 usually kept packed in a case, and only hoisted on the approacli 

 of danger, which it may then be too late fully to avert. To 

 remedy these inconveniencies, Mr. Harris proposes to place in 

 the back of the masts a slip of copper, which is to be continuetl 

 to the interior or hole of the cap of each mast ; consequently, 

 coming into contact with the mast above, the continuity will 

 be preserved without the upper masts being lowered. The 

 conductors of the lower masts are to be continued to the keel, 

 and made to communicate with one or more copper bolts in 

 contact with the exterior copper or the water. It must be 

 clear, therefore, that this arrangement preserves a permanent 

 conductor so long as any part of the mast is continued; and as 

 the masts of a ship may be considered as mere points when 

 contrasted with a tlnmder cloud, thus armed they are virtually 

 pointed conductors. To those acquainted with the action of 

 points on charged electrics, it will be obvious, and not too 

 much to presume, that such masts will be highly efficacious in 

 silently depriving a thunder cloud of its charge, thereby giving 

 to ships a degree of security of very considerable imjiortance. 

 From these considerations Mr. Harris was induced to sub- 

 mit a model of a complete mast, furnished with permanent con- 

 ductors, to the inspection of the Honourable Navy Board, who 

 expressed their decided approbation of the }n'inciple, and re- 

 quested him to exemplify its efficiency by an experiment, which 

 was carried into effect, on Monday September 16, on board 

 the Caledonia, at Plymouth, in the presence of the Navy Board, 

 Sir A. Cochrane, Commissioner Shield, several Captains in 

 the Navy, and the principal officers of the Dock-yard, in the 

 following manner :^The Louisa cutter having had a tem- 

 porary mast and topmast fitted with a copper conductor, ac- 

 cording to Mr. Harris's plan, was moored astern of the Cale- 

 donia, and at the distance of eighty feet from the cutler a boat 

 was stationed with a small brass howitzer. On the tiller head 

 of the Caledonia were placed the electrical machine and an 

 electrical jar, with the outer coating of which a line was con- 

 nected, having a metallic wire woven in it : this line being 

 carried out of the starboard window of the wardroom, termi- 

 nated in an insulated pointed wire in the immediate vicinity of 

 the touch-hole of the howitzer; a similar line was passed from 

 the larboard window, which communicated with tlie mast head 

 of the cutter : and at the termination of the bolt through the 

 keel, a chain was attached, connected with another insulated 

 pointed wire in the boat, placed in the vicinity of the touch- 

 hole — the space between the insulated points being the only 

 mterval in a circuit of about 300 feet, from the positive to the 



negative 



