The Construction of the Crossbow
chase. On the other hand, many of the military crossbows had straight
bows, which were merely canted upwards in their stocks to enable their
bow-strings to work freely. The latter plan did not, however, give so straight
a pull and so fair a strain to the bow, as the one described in fig. 58.
To procure a good bow of spring steel of correct size and shape, it
should be first modelled in wood. The model should then be sent to a spring
maker to copy, with instructions to temper the steel a little soft, so
that the bow may take a slight ' set,' rather than break, if overstrained.
Liege in Belgium is the best place from which to obtain a trustworthy
bow.
Fig. 59. - Surface, Side and Side-Section of One of
the Bow Irons. Scale 1/4 in = 1 in.
There are two of these irons, one on either side of the stock. They
are each 7 in. long, 1/4 in. thick, 1/2 in. wide all round their sides
and 1/2 in. wide between the narrow parts of their openings.
The wide openings of the irons, at their large ends, exactly fit the
width of the bow (1 5/8 in.) at its centre.
The irons surround the centre of the bow, as well as the corners of
the base of the stirrup. The base of the stirrup rests upon the centre
of the back of the bow.
The bow-irons act as straps to pull, and then immovably hold, the bow
and its stirrup tight against the stock of the crossbow, this being achieved
by the metal wedges presently described, figs. 61, 62, 63, p. 106.
When the bow, the bow-irons and the stirrup, are in position on the
stock of the crossbow and ready for the wedges to be applied which secure
them, the narrow ends of the openings in the bow-irons should each be 3/4
in. |