and. It spanned the brook at the gorge, and was therefore a more
difficult engineering feat. Mr. Schreiner himself asked us to build it,
and we felt greatly honored by the request. A search was made in the Van
Syckel library for a suitable type. At last we found one that seemed
properly suited to the requirements. It was called a "king post truss,"
and was very similar to the king rod bridge. While the design of the
bridge was simple, yet it required some ingenuity to put it together. In
setting up the other bridge the scow had been anchored in the center of
the stream and used as a working platform, from which it had been an
easy matter to put the various parts together. In this case our scow was
obviously of no use, so we laid a couple of long logs across the chasm,
and a few slats were nailed across them to provide a temporary bridge or
working platform. The platform sagged considerably at the center,
because the span was fully eighteen feet; but the logs were large, and
we knew they were strong enough to support our weight. However, as an
extra precaution, we tied the ends to stakes driven in the ground, so
that they could not possibly slip off the banks.

[Illustration: Fig. 101. The King Post Frame.]

[Illustration: Fig. 102. The King Posts Set in Position.]

[Illustration: Fig. 103. The Permanent Cross Beam Made Fast.]

First we set about constructing the king posts, which were made as shown
in Fig. 101. Two stout posts 7 feet long were connected at the top by a
tie stick, which spaced them 4 feet apart. To make a secure fastening
they were notched together and strengthened with diagonal braces. Each
king post was notched on opposite sides, at about thirty inches from the
top. A temporary tie piece was also nailed across the lower ends of the
king posts. The frame thus formed was set up at the center of the span
and temporarily held by nailing the lower tie piece to the working
platform. Four stout spars were now cut, each about fifteen feet long.
Taking a pair at a time, we planted their lower ends firmly in the
opposite banks and sawed off their upper ends until they could just be
hammered into the notches in the king post. This required careful
fitting, but by making the spars a little too long to start with, and
then shaving them down with a draw-knife, we managed to make fairly good
joints. A couple of long wire nails in each spar made the structure
perfectly secure. The king posts were now sawed off just