The banks were
very precipitous, and rose 13-1/2 feet above the level of the water. All
these details, together with soundings of the bottom, all the way across,
were sent to Uncle Ed, and on the day after our railway was completed
quite a bulky package was received in answer. It contained complete
directions for building the bridge of wooden frames, which were so
designed that they needed merely to be hooked together to form the bridge,
though to make the structure perfectly safe Uncle Ed cautioned us to tie
the frames together wherever they met.
I am half afraid to tell my readers how to build this bridge, as it
required the utmost care, and had to be built just so to avoid disaster.
Bridge building is a serious business, and I would not advise anyone to
attempt building this, of all bridges, who does not propose to follow
instructions implicitly. Uncle Ed told us that if we built it properly,
and with sound timbers, we would find the bridge strong enough to support
a dozen boys, but he warned us not to crowd more than that number on it.
Frames for the Cantilever Bridge.
[Illustration: Fig. 305. A Frame (make four).]
[Illustration: Fig. 306. B Frame (make four).]
[Illustration: Fig.
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