SIO Mr Harris on the Utility of fixing 



awful to an ordinary observer, the electrician sits quietly in front 

 of the apparatus, conducts the lightning in any required direc- 

 tion, and employs it to fuse wires, decompose fluids, or fire in- 

 flammable substances ; and when the efifects become too power- 

 ful to attend to such experiments, he then connects the insulated 

 wire with the ground, and transmits the accumulated electricity 

 in silence and safety *."" 



31. It may be laid down as an axiom, that a lightning-con- 

 ductor can always transmit a quantity of electricity equal to its 

 fusion. This is evident, because the fusion has been the conse- 

 quence of the quantity actually transmitted : now, on a review 

 of all the cases of damage by lightning, it cannot be said that 

 we have any evidence whatever to believe, that a conductor, 

 equal to a copper-bolt of 1 .3 of an inch diameter, and 210 feet 

 long, which may be taken as the mean value of the conductor 

 on one mast of a fifty-gun frigate, is at all likely to be fused. 

 If we add to this the conjoint action of the conductors on each 

 mast, and the favourable conditions under which they are placed, 

 — that is, their termination in points above, and in a free unin- 

 sulated base below, — we have every reasonable evidence that 

 such conductors are fully equivalent to the ends in view, and 

 that instead of the disastrous effects which are usually expe- 

 rienced from a stroke of lightning, the electric matter would be 

 transmitted in the greater number of instances in a state of low 

 tension to the sea, so that no explosion would occur at all. If, 

 on the contrary, we could reasonably suppose such conductors 

 to be destroyed, then it may still be inquired, (since even in this 

 case they must be supposed to have transmitted the lightning), 

 what would have been the fate of the vessel if such conductors 

 had not been present ? 



32. It is a mistake to suppose, that, in fixing conductors in 

 the mast, we can only have surface, as will be seen by reference 



• The authority of Professor Leslie has been quoted by some writers 

 against lightning-conductors, but this eminent philosopher has too high a 

 conception of great natural causes, to reason in the confined way attributed 

 to him. It is true, that from some very ingenious researches on the nature 

 of electricity, he is led to believe that lightning-rods are not of great avail ; 

 but he considers them to be quite harmless, and observes " that they provoke 

 the shaft of heaven is the suggestion oi superstition ratlier than of science." 



