CHAPTER I.

Concerning the new invention of Sluices.

To clearly explain wherein this new invention of Sluices Gates used to control water levels; in this context, they are used for both land management and maritime defense. lies, I say first that their use consists of three principal varieties, namely: for deepening Harbors, for drying low-lying waterlogged Lands; and for passing through Ships with their masts upright. The first variety, for deepening Harbors, has for a long time been performed most conveniently with Sluice gates hoisted upward, as shown by this 1st Figure, the use of which is thus: The gate being hoisted upward, and the flood tide original: "flux". The incoming tide from the sea. flowing into the reservoir until it is at its highest, the gate is lowered, leaving it closed until the ebb tide original: "reflux". The outgoing tide. is at its lowest; and then, the gate being hoisted upward, the water held in the reservoir falls into the dry Harbor and deepens it This process of "scouring" uses the force of released water to wash away silt and sand from the harbor floor.. This deepening is also done with rainwater, or from small Rivers; having gathered enough in the reservoir, one acts as before. But through such Sluices, large Ships with upright masts cannot pass, because of the obstruction of the gate and the axle original: "effieu". The horizontal shaft of the windlass used to lift the gate. by which it is hoisted upward.

A woodcut technical illustration of a wooden sluice gate. The image shows a tall vertical wooden frame with a sliding gate positioned inside. Above the gate, a horizontal windlass (axle) is mounted with a handle on the right side for manual cranking. Ropes are attached to the axle and descend to the top of the sliding gate, showing how it is hoisted upwards.