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In surveying the immense coast line of the United States, the U.S. Coast Survey, then under the direction of Prof. Bache, undoubtedly initiated the first systematic endeavour to grapple with this important problem; and Lieut. Maury, of the National Observatory, seizing the opportunity, proposed that strong twine, made expressly for the purpose, should be used with 32 lb. and 68 lb. shot for sinkers, and, instead of sounding from the ship, he suggested the work should be done from a boat; the idea being that the boat could be kept directly over the line by means of the oars, and the twine being so small and light in proportion to the weight of the sinker, the shock of striking might be felt as it ran through the hand the twine to be cut when bottom was reached, without trying to haul it back; thus a proportionately heavier sinker could be used than with the methods previously in vogue.
The U. S. brig Dolphin, under the command of Lieutenant, now Rear-Admiral, S. P. Lee, U.S.N., was the first to try that experiment, and after a number of failures which tested the patience and skill of that officer to the utmost, he finally succeeded, and the results obtained by that vessel were probably the most reliable which had been obtained up to that time. But this success lacked one important feature; specimens of the bottom were needed, not only to put beyond doubt the accuracy of the sounding, but to bring to the light of investigation the character of the soil from the ocean bed.
Then it was that, Lieutenant J. M. Brooke, U.S.N., invented the simple and beautiful contrivance of detaching the sinker and dropping it on the bottom, leaving a small rod, hollowed out at the bottom, in which were fixed open quills, to be hawed back on board by the twine. In the act of striking, the quills would fill with mud, and retain it till drawn up to the surface.
Lieutenant, now Rear-Admiral, B. F. Sands, U.S.N., also devised an apparatus by which a split sinker was made to fall apart when it touched bottom, leaving a cup, ingeniously arranged to bring up specimens of the bottom,
