Conducting Rods. 369 



position. July 15th, a locust was split in Hamilton, 80 rods from 

 Dea. Lorinor's house. A laro-e elm was struck at Dedham. 



In every instance of the passage of lightning through trees, 

 brought to the attention of the Committee, the tree has been found 

 to suffer to a greater or less extent. 



If then we find the tree incapable from its conducting power, 

 of defending itself, we should judge that lightning would need 

 little inducement to forsake it for a building in which iron to a 

 greater or less extent is employed ; nay, even animals in the 

 vicinity of trees would be exposed to greater danger than in an 

 exposed situation in the open air ; for the tree by its great height 

 would first receive the shock, but would not withhold it from an 

 animal within the sphere of attraction. The Committee would 

 therefore decide the second question in the negative. 



3. "Whose rods, and of what construction have afforded the 

 greatest security ? 



The best rods or those which have stood longest the test of 

 time were invented by King Solomon ; for the temple, was 

 unharmed by lightning during one thousand years. The whole 

 roof bristled with metallic pinnacles, the body of the building was 

 covered with plates of gold, and water spouts from the roof de- 

 scended into deep cisterns of water. This was the system of Solo- 

 mon. 



If then we elevate a sufficient number of points to furnish a pass- 

 age for the electric fluid, and with surface sufficient to prevent 

 any part of it from seizing some iron bar, zinc roof, tinned porch 

 or widow-casing, we have complied with one essential condition ; 

 if we keep open a sufficient number of these passages to the earth, 

 and spread the rods into points below as above, we have answered 

 another condition. If different parts of the house are furnished 

 with metals, these substances should be united by wires with one 

 of the main trunks; if, however, we insulate the system with con- 

 ductors, furnish a sufficient number of them, and thus prevent the 

 fluid from reaching the imperfect conductors within the building, 

 we shall have answered the same purpose. 



An excellent system of conduction for our buildings is that of 

 George W. Otis ; for ships that of W. G. Harris. 



The rods of the former are constructed from 3-8 in. iron, elevat- 

 ed above each chimney, the points of the ridge pole and other 

 prominent elevations, presenting either a branch of points or a 

 single point, gilt, extending over the ridge-pole down the rafters 



D 



