Canoe Sailing Rig: Bamboo Mast, 9 ft Lateen Sail, Clamp-In Mast Thwart and Leeboards (Boy Mechanic, 1919)

"The lateen rig is best for an open canoe, because a shorter mast is required for the same sail area ... It is not safe to rig a canoe too heavily, and the rig described has been found to be well proportioned."

Cut bamboo 1-1/2 in across to 6 ft 10 in (carpet dealers' rolling bamboo of 1-1/2 to 2 in serves). Whittle a tapered wooden plug about 3 in long to wedge firmly in the top without splitting the cane, bore a small hole through the cane 2 in from the top, and fix a screw eye into the plug for the halyard. Drive small brads through the cane into the plug, and fit a brass ferrule over the end.

Use two bamboo fishing rods, 1 in at the butt and 10 ft long, as gaff and boom. Fix a 1-1/2 in screw eye with a 1/2 in eye at the end of each and join the spar ends with a 1-1/2 in brass split ring and a 1-3/4 in brass S hook. Fasten the 2 in brass boom jaw on the boom with its open end 18 in from the boom's forward end.

Lay the spars on the cloth and pencil a triangle 9 ft on each side. Sew the widths of 1 yd unbleached cotton sheeting together, lapped about 1/2 in and stitched close to both edges, preferably on a machine. Sew bights (folds) 1/2 in wide, 6 in apart, parallel with the leech. Reinforce the corners with segments of cloth. Along the edges lashed to the spars fold and sew 1 in hems, running a 1/2 in tape into the leech hem; fasten the tape to the spar at each end to take up stretch and stop a flapping leech.

Mast thwart: two cedar or pine boards 28 by 10 by 3/8 in and a piece 27-1/2 by 3-1/2 by 3/4 in, made as in the plate with a hole in the centre for the mast and a brass lantern-board hook at each end to clamp it to the gunwales. Mast step: a block 5 by 2-1/2 by 1 in, shaped neatly, fixed to the grating (or the ribs). Leeboard thwart: cedar or white pine 5 ft by 4 by 7/8 in, with short upright ends set at an angle to the canoe's curve so it wedges in just aft of the mast; groove the ends to the thwart and screw them on. He gives no leeboard sizes; bolt a leeboard to each end with a 3 in by 5/16 in brass bolt, washer and thumb nut so its angle can be set.

Smooth all woodwork with sharp tools, sandpaper lightly, and give three coats of spar varnish. Lash the sail to the spars, run the 1/4 in cotton-rope halyard through the screw eye at the masthead until the gaff is close to the top, and find the balance by tying the halyard at different points along the gaff. Run the halyard under the forward thwart to the stern, never tied to it, and loop the main sheet round a thwart and hold it, never made fast.

From "How to Build a Canoe, Part II" by Stillman Taylor, in **The Boy Mechanic, Book 3**, Popular Mechanics, 1919 (Project Gutenberg 71856; checked on the archive.org scan boymechanic0003unse, pp. 86-88). He gives no leeboard sizes (they vary with the canoe); the list calls the leeboard bolts brass stove bolts with thumb nuts and the text carriage bolts with wing nuts. Cedar for the leeboards, the sail area and the metric figures are ours.