OF THE LATE MB. WILLIAM STUBGEON. 7 1 



and zinc, in the proportion of 1 to 7, was found to be quite 

 destitute of magnetic action. 



In 1839 he published a memoir " On Marine Lightning 

 Conductors," comprising an examination of the effects of 

 lightning on shipping, with remarks on Mr. Harris's plan; 

 and the description of a new system of conductors. Mr. 

 (now Sir W. Snow) Harris, following Mr. Henley, placed a 

 strip of copper into a groove let into each mast. An elec- 

 trical discharge striking the top of the mast was thus to be 

 conducted by the copper strip through the keel into the 

 water. In the system recommended by Mr. Sturgeon, cop- 

 per rods or metallic ropes are placed aft the shrouds of each 

 mast. The upper extremities of these conductors are at- 

 tached to the fore, main, and mizen tops, as distant from the 

 masts as circumstances will allow. The lower ends are con- 

 nected with the chains belonging to the aft shrouds of each 

 mast, and continued by broad and stout straps of copper to 

 the sheathing of the ship. The top and top-gallant masts 

 are protected in a similar manner, their conductors being 

 connected with those of the lower masts. If, therefore, light- 

 ning strike the top-gallant, it will descend in two streams on 

 either side of the mast, and then over the sides into the sea. 

 Lastly, in order to distribute the discharge as completely as 

 possible, and thus still further to lessen its danger, he proposed 

 to unite the conductors of the fore, main, and mizen, by means 

 of copper rods or metallic ropes in the position of stays. 

 Little attention seems to have been paid to the above system, 

 which, nevertheless, secures many highly important advan- 

 tages, of which the following may be enumerated. 1st. The 

 conductors being for the most part entirely removed from any 

 combustible material, and combined so as to divide amongst 

 them any stroke of lightning, the danger of fire in consequence 

 of lateral discharge is less to be apprehended. 2nd. The 

 electric fluid is carried over the side of the vessel, which 



