52o 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 cir- 

 cuits 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 ex- 

 pensive 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- 



