Canal Works: Locks, Excavation and Siphons
Estimates for digging a canal — a water-raising wheel, five locks in 70 braccia, and portable siphons
Working notes for a canal project. A water-raising wheel is sized — hub 1,000 pounds, windlass 2 braccia, wheel 4, lifting 2,000 pounds of water with the hub moving 6 and 1/7 braccia. Further notes plan five locks within 70 braccia, with the inflow meeting the standing water at a right angle, propose clearing spoil through wooden chutes a b, and finish a trial stretch (25 braccia wide, 4 deep, 2 long) to gauge true cost and time before the contract is let. A closing note calls for four or six portable siphons a b c d.
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A water-raising wheel and its reckoning
The mechanism is sized numerically: let the hub be 1,000 pounds, the windlass 2 braccia and the wheel 4, with the water it carries at 2,000 pounds. The motion of the hub is given as 6 and 1/7 braccia.
Five locks within seventy braccia
Within 70 braccia five locks are to be set, arranged so that the water pouring in from the bottom of the well enters beneath the standing water at a right angle. The upright of the well, 12 braccia high, is to meet the line of the discharged water's motion at a right angle.
Clearing spoil and pricing a trial stretch before the tender
Spoil is to be cleared away through wooden chutes a b. One trial part, on a shore of moderate difficulty and cost, is to be finished 25 braccia wide, 4 deep and 2 long, so that the true cost and time may be seen before the contract is put up for tender.
Four or six portable siphons
For the undertaking of the whole work, four or six siphons a b c d are to be made. They are to be portable so they can be moved along the works.