The Frame of the Yacht.

[Illustration:  Fig. 215.  The Backbone and Crosspiece.]

I followed him to the shed at the back of the school and found that he had already procured a couple of scantlings for the frame of the boat.  The sticks were 2 inches thick and 4 inches wide.  The backbone was cut to a length of 10 feet, and a 5-foot link was sawed off for the crosspiece.  The two pieces were securely nailed together about 3 feet from the forward end of the backbone.  The crosspiece was set on edge, but a notch was cut in it about 1 inch deep to receive the backbone.  We might have braced the frame with wooden braces, as in the ice boat, but we thought that this time we would vary the design by using wire bracing instead, thus making the frame much lighter.  I asked Bill how he proposed to tighten the wire.  Turnbuckles were the thing, but I knew that they were rather expensive.

“Just you leave that to me,” said Bill.  “I’ve a scheme that I think will work out all right.”

A Simple Turnbuckle.

[Illustration:  Fig. 216.  An Eye Bolt.]

[Illustration:  Fig. 217.  Stretching the Guy Lines.]

At the hardware store of the town we bought a pound of No. 16 iron wire, eight large screw eyes and six eye bolts, with nuts and washers.  Both the screw eyes and eye bolts had welded eyes and the shanks of the eye bolts were 6 inches long.  A pair of screw eyes were now threaded into the backbone at each side about 18 inches from the end, and at each end of the crosspieces an eye bolt was fastened.  I began to see Bill’s plan.  He was going to draw the wire taut by tightening up the nuts on the eye bolts.  To get the best effect the hole for the eye bolt had to be drilled in on a slant, so that the bolt would pull directly in the line of the wire.  To get just the right angle we ran a cord from the screw eye on one side to the point where the bolt was to be inserted, and traced its direction on the crosspiece.  The hole for the eye bolt was now drilled parallel with the mark we had traced.  The same was done at the other end of the crosspiece.  A pair of screw eyes were now screwed into the backbone at the fore end and a pair of eye bolts were set at a corresponding angle in the ends of the crosspiece.  The crosspiece was notched at each side so that the nuts and washers on the eye bolts would have a square seating.  Then we stretched on the wire guy lines, drawing them as tight as possible, with the eye bolts held in place by a turn or two of the nuts, after which we screwed up the nuts as far as we could, thus drawing up the wire until it was very taut.  This done the second nut was threaded onto each bolt against the first so as to lock it in place and prevent it from jarring loose.

Stepping the Mast.