The 25th Improvement

Consists in making a temporary rudder, which is composed of two fins, out of some short pieces of plank placed over each other crosswise, and bolted or nailed together. As the fins of a temporary rudder will be attached to the sides of the vessel, one fin on each side, and as therefore they will be nearer the surface of the water, their size must be larger than if the fins were near the keel.

In one side of each fin there are holes to reeve large rope or small chain, which is to serve the purpose of hinges and to keep the fins in a vertical position in the water, and they are then fastened to part of a bower cable which is put overboard, and brought round the vessel's bottom, abreast of the foremast and then bowsed taut. A rope-guy from the outer end of each fin leads adt where the guy is fixed, to prevent the fin's traversing forward beyonf an angle of about ninety degrees from the vessel's side -- and there is a rope leading forward from the outer end of each fin to a block at the end of a topsail-yard, temporarily fixed on the deck a short distance abaft the stem, which latter rope leads inboard to a tackle or tiller, and thus the vessel is steered.

Shipwreck and Collisions at Sea greatly prevented by Christophers' Patent Improvements in Naval Archtecture. With four plates.
London: J. Olliver, 59, Pall Mall; P. Richardson, 23, Cornhill. Liverpool: Deighton & Laughton. M.DCCC.L. 8vo, (4), 112 p, 4 pl.

Transcribed by Lars Bruzelius

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