The telegraph manual: a complete history and description of the semaphoric, electric and magnetic telegraphs of Europe, Asia, Africa, and America, ancient and modern.

520 ELECTRIC TELEGRAPH CONDUCTORS.
the trials, as to the strength of the wires, are given in the
accompanying tables. To test the wire, an ordinary steelyard
was employed, as represented by fig. 1: A is a suspended timber, to which was swung the steelyard; B is the wire undergoing the test; c is an upright timber; D is an iron rod fastened to the joist. At the lower end of the rod D is an opening
through which the beam is passed. This opening is scaled to
limit the movement of the beam within a foot. Whenever the
wire stretches and lets the beam descend to the lower end of
the opening, the screws at c can re-adjust the scale so as to
allow the weight to again bring down the lever beam to its
limit. The wire frequently broke within the clamps, and could
not be counted. Only the breaks that occurred at B were recorded. The averages of these trials are given in the table.
Table 6 shows some tests of wire not as strong as the wire of
the other trials. The wire of each kind, viz.: Swedish
and American, was from the same qualities and the same
lot of iron. The difference in the strength, is owing to the
manner of drawing. Messrs. Washburn & Co. have attained
this superiority of strength by many years of careful experiment. Most of the telegraph wire used in America is manufactured by these gentlemen, and the peculiar wants of the
enterprise have been carefully studied and accommodated by
special arrangements. It is important for telegraphers to consider the peculiar wants of their line, and to have the wire
manufactured to meet every contingency. Mr. P. L. Moen, of
the above-named firm, informs me that the toughness of the
wire depends as much upon the drawing, as upon the quality
of the metal. I have frequently visited their establishment, and
have been highly gratified to see the great care exercised t!)
attain the greatest degree of perfection in the manufacture of
the wire to meet the especial wants of the telegraph. The
telegraphic enterprise has reason to rejoice that these gentlemen have done so much and are continuing their attentions,
regardless of expense, toward the accomplishment of every consideration, having in view the perfection of the art of telegraphing, so far as can be attained in their specialty.
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wire. No builder would use un-annealed wire, nor would an)
company have any other kind employed. It was required t(
be well annealed, and the more pliable it was, the more accept.
able. The experiments given in Table 4 show how great wam
the folly of the earlier ideas relative to the use of annealec
wire. It cannot be denied, however, but what the wire shoulk
be slightly annealed, so that the joints can be made with rea