Proceedings of the Polytechndc Association. 807 



Mr. Moses G. Farmer, of the city of Boston, a man who is second 

 to none in his knowledge of all that pertains to electro-magnetism, 

 has supplied that which has been so long wanted — a good, strong, 

 cheap and light telegraph wire. In the specimen now exhibited we 

 have a mile of wire M^onnd in a coil, which is so light that a man 

 can carry it on his shoulder. The ordinary telegraph wire of this 

 length would weigh over one hundred pounds. 'W'lien all other kind 

 of M'ires failed on the great California line, this fine wire succeeded. 

 This wire is made of fine steel, which is very strong ; after being 

 drawn to the required thickness, it is passed through a btitli of pure 

 tin, with which it becomes coated ; then a ribbon of copper is rolled 

 out and drawn over the steel wire, through a die ; the wire is then 

 passed through a bath of chloride of zinc, which cleans the surface 

 and at the same time solders the copper to the steel. Thus we have 

 a wire possessing the continuity of copper with the strength of steel. 

 This wire has seven times the conductivity of iron, and is so light 

 that it can be mounted on posts of but twelve to fourteen to the mile. 

 , Mr. Farmer has succeeded so well thus far, that there is every pros- 

 pect of his making a conductor that wall not require a repeater 

 between here and San Francisco ; a wire that will Avork wdtli as 

 much certainty as that between here and Albany. 



LiGHTNmG Rods. 



Dr. Boynton also presented some lightning rod wire, and said : 

 "While he was making some experiments in regard to lightning con- 

 ductors, he noticed the cases where buildings were struck with light- 

 ning when they had rods on them. But he always found in such 

 instances that the conductors w^ere not made of proper materials. 

 On being shown the telegraph wire of Mr. Farmer, he immediately 

 saw that that was the article wanted to make a perfect lightning 

 rod. The wire here shown is made of .'N'o. 7 iron wire. He has 

 secured its use exclusively for lightning rods. The iron is tinned and 

 copper put on it, and the copper is then tinned on the outside. And 

 here is all that is required for a perfect lightning rod — sti-ong, free 

 from oxydation, and one continuous rod without any nuts or joints 

 whatever. Two wires are twisted together, forming a very strong 

 and durable rod. The machine for twisting these wires has been 

 running but a few days, yet the demand for the rods is so great that 

 it cannot be supplied. 



Prof. Phin remarked that the question of telegraph wires was one 



