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Page:Popular Science Monthly Volume 70.djvu/524

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520
POPULAR SCIENCE MONTHLY
the cost of poles, which can usually be obtained in your own locality, using twenty-five 25-foot, 5-inch top poles to the mile:
165 lbs. No. 12 galvanized B. B. iron wire $6.80
25 Oak brackets .30
25 Pony glass insulators .37
25 60-penny and 25 40-penny nails .25 $7.72

On February 1, 1878, the Bell Telephone Company of Boston, the second of the parent associations, issued circular No. 3, reading in part:

When the (District telegraph) company does not desire (to introduce) the Bell telephone, a District telephone company should be organized, and metallic circuits constructed, running from the central office to various parts of the city. . . . The stock to be issued for the cost, in any case, should not exceed one hundred dollars a mile of wire, including all fixtures.

Evidently good telephone line construction was considered too expensive to justify introducing the telephone in many places, for one year later, the parent company issued a circular bearing the caption 'Telephonic Exchange System,' and detailing a combination of the advantages of the different exchanges in operation. Therein it barely touched upon the construction of line circuits, but called attention to the now well-known fact 'that repairs on line' are part of the current expense, an item that companies organized during late years have been prone to charge to construction and capitalize. But later, in 1879, the third parent company issued a pamphlet of instructions from which the following item is taken:

The line wire generally used is the No. 12 galvanized iron, and a line built of this wire, if securely put up, will last for years without repairs. Where a cheaper line is desired, No. 14 or 16 iron wire, or a small copper or brass wire may be used, but smaller wires than No. 12 are very liable to be broken by storms and high winds, and it is always cheaper in the end to use wire at least as large as No. 12. In towns or cities the wire can be run over house-tops, using small glass pony insulators and wooden brackets. About thirty of these insulators and brackets are needed for a line one mile long. They can be nailed to the side of a chimney, to the ridge-pole or side of a house, or to a pole. When there are no houses to support the wire, poles must be used. These are generally about twenty feet long, four inches in diameter at the top, and are set four feet into the ground. Care should be taken to keep the wire from touching anything except the glass insulators. The line wire should terminate on the outside of the stations, and the connections be made to the instruments by No. 16 or No. 18 insulated office wire, which is wound tightly around the iron wire and soldered.

Possibly construction of so cheap a character was too costly to meet the approval of many early operating companies, so to meet this uneconomical demand for cheapness regardless of permanency, a new set of instructions was issued by the parent company, which read, in part, as follows:

Lines up to six miles in length can be built of No. 14 galvanized iron B. B. wire. Lines over six miles and not over 25 miles should be built either of No. 11 or No. 12 galvanized iron B. B. wire. Lines over 25 miles in length should be built of No. 11 galvanized iron B. B. wire. We recommend the use of porcelain in-