UNDERGROUND ELECTRICAL WIRES. 651 



unsuitable. Earthenware was employed with considerable promise 

 of success but was found open to such serious objections tliat it 

 was abandoned, and iron pipes have been universally used for 

 many years. Of the different insulators employed gutta percha 

 and india rubber have been the most successful and are now 

 almost universally used to insulate wires, either pure or mixed 

 with some other material. Paratfin and asphalte have also been 

 tried and under certain conditions with success. 



In 1875 I find from a paper read in December of that year, 

 before the Society of Telepraph Engineers by Mr. Charles Fleetwood 

 of the London Post Office Telegraph, that there were in London 

 three thousand five hundred miles of wire laid underground in 

 iron pipes. These wires were of copper, No. 18 gauge, covered 

 with gutta percha to No. 7 gauge. Mr. Fleetwood described the 

 method of laying the wires, and as that method is still employed 

 in England, I would refer those interested to Mr. Fleetwood's 

 paper. This may be found in the Proceedings of the Society of 

 Telegraph Engineers for 1875, together with the discussion upon it 

 by many prominent members. 



I find that much stress is laid upon the advisability of using 

 iron and not earthenware pipes, upon the fact that the pipes 

 should not be more than four inches in diameter, and upon the 

 very great difficulty of making good joints anywhere, especially 

 in the streets wherein curious people passing interfere with the 

 jointer, and where the wet and dirt almost prevent good joint 

 making. 



So long as telegraph "wdres only had to be dealt with, the English. 

 Post Office autliorities were able to keep the nuisance of overhead 

 wires within bounds, but the introduction of telephones promised 

 to so rapidly increase the number of wires required in the streets, 

 that municipal authorities began to agitate for a more rapid 

 extension of the underground system, and in 188-5 a Committee 

 of the House of Commons was appointed to consider the question 

 of underground telegraph and telephone wiies. The Committee 

 took a great deal of evidence and reported in favour of the 

 continuance of the system of overhead wires subject to proper 

 supervision. During the discussion by the Committee it was pro- 

 posed that where more than ten wires run along a line, the local 

 authorities should have power to compel them to be taken under- 

 ground. This proposal was negatived. Evidence was given before 

 this Committee by most or the leading engineers and experts 

 interested in the question, and their opinions clearly proved 

 that the difficulty and cost of placing wires undei ground was such 

 that there is little room for wonder that the Committee oould not 

 recommend the passing of an Act of Parliament to compel the 

 placing of wires underground. It was doubtless felt that such an 

 Act would pi'actically prevent the extention of telegraphs and 

 telephones. 



