Lead Encased Conductors
Transactions of the American Institute of Electrical Engineers
In the first attempt in this country to work electric telegraphy, by Professor Morse, the wires were covered with cotton, soaked in a preparation of shellac, drawn into lead tubes four together, the intervening space being left empty. This system was laid from Baltimore towards Washington, about five miles on the Baltimore and Ohio Railroad. I got this information from Tatham and Bros., who inade most of the lead pipe purchased, altlhough none of what they made was laid. The experitnent was a
... experitnent was a failure. About that time, or a little before, Professor Jacoby, of St. Petersburgh, undertook to lay cotton-covered copper conductors in lead pipe witlh the intervening space filled with rosin. There have been very many attempts of that kind which proved to be failures, uintil thie year 1856, when the discovery of petroleum brought parafline into the market as a cheap commercial product. This was brought to my notice, and I made many experiments to test its insulating properties, and as the resuilt, it was taken to the patent office, and the patent awarded me, broadly, for its insuilating properties. It occurred to me that cottoni-covered wires could be drawn into lead pipe, and a useful system for underground purposes accomplished, but before ruslhing to the patent office, specimens were buried in the yard of my factory directly under a body of water, or earth soaked with water from a hydrant. Tllese experiments were repeated, and for a lonig time were attended with failure.