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Application for a Patent

What I claim as my invention, and desire to secure by letters patent, is the combination of expansible buoyant chambers placed at the sides of a vessel with the main shaft or shafts by means of the sliding spars, which pass down through the buoyant chambers and are made fast to their bottoms and the series of ropes and pulleys or their equivalents in such a manner that by turning the main shaft or shafts in one direction the buoyant chambers will be forced downwards into the water, and at the same time expanded and filled with air for buoying up

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the vessel by the displacement of water, and by turning the shafts in an opposite direction the buoyant chambers will be contracted into a small space and secured against injury.

A. LINCOLN.

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Notes

1. The invention that Lincoln patented was an improvement for lifting vessels over shoals. The inscription above the model in the Patent Office states it was patented by Lincoln, May 22, 1849. The apparatus consists of a bellows on either side of the hull of a craft just below the water line which is controlled by a simple and unique system of pulleys. These air repositories are intended to buoy up the vessels when in danger of grounding on reef or other obstruction. The model is about eighteen or twenty inches in length and appears to have been whittled out of a shingle and a cigar box.