p. 269 | Deep Sea Soundings

International Tract and Missionary Society · Oakland, California · May 6, 1886

FromSigns of the Times, Vol. 12, No. 17.

Deep Sea Soundings.

SOUNDINGS are taken with iron balls similar to nine-inch shot slung with wire. A hole three inches in diameter through the middle of the ball reduces its weight from ninety-six pounds (the weight of nine-inch shot) to sixty-four pounds. Through this hole a brass plunger several inches longer than the diameter of the shot is inserted. The plunger is filled with a worm, a cup, and a hook by which the shot is fastened to a reel containing 5,000 fathoms of steel wire fastened to a swivel forming the head of the plunger and led over a wheel in an iron frame several feet clear of the ship's side, and over another wheel a little below the frame. This leads the wire still further clear of the ship. The frame on which the upper wheel hangs has five hollow stanchions in which are springs, to each of which a rope is fastened, roll over roll, as in the top of the frame, and to which the wheel hangs so as to give way several feet to pass the strain which naturally comes on the wire, and would surely break it on a heavy roll of the ship, as it has done once, causing a loss of 1,600 fathoms of wire. When everything is ready, the shot is dropped overboard, and the wire runs off the reel at the rate of 1,000 fathoms in ten minutes. As soon as the plunger reaches the bottom, the hook to which the shot is fastened turns over by the slackening of the strain, and so releases it. A telltale on the axle of the reel tells how many fathoms of wire have run off. A little steam engine then winds the wire with the plunger on the reel, minus the shot which forever remains at the bottom of the ocean. The plunger consists of a hollow brass tube ten inches long, in which is inserted a worm with a cup on the lower end. The worm serves for the purpose of twisting the cup into the bed of the ocean and so fetch up a sample from the bottom. The cup is the invention of Lieutenant Belknap, United States Navy, and named after him. He has invented three different cups, but the one used on board the Enterprise is Belknap cup No. 2, and the best adapted for the purpose. The contents of the cup, after the water is drained off, are put in small bottles and labeled with latitude, longitude, and depth. These bottles are packed into boxes, to be sent to the hydrographic office in Washington.

When under steam alone the engines are stopped for sounding, but when under sail alone steam has to be gotten up and all sail taken in, as the ship has to be perfectly quiet, and to be under control, which is impossible under sail. Soundings were taken about every 100 miles, the depth usually being two or three thousand fathoms. The greatest encountered was 3,800 fathoms, or about four and a half miles. In latitude 30 degrees south and longitude 30 degrees west, shoal water of about 400 or 500 fathoms was found, revealing the existence of a range of mountains on the bottom of the ocean. (These the Challenger, an English man-of-war, on a deep-sea sounding expedition around the world ten years ago, had failed to discover.) That day fifteen soundings were taken, one every five miles, till deep water was reached again. The cost of a shot is $4.00. Lieutenant Marix, the navigator, had charge of the work, and it required a quartermaster, an assistant, and a fireman to run the engine to take a sounding, which altogether lasts about one hour. Should the shot fail to discharge, as it did once during the cruise, the whole has to be wound up again by hand, which takes three hours for a depth of 3,000 fathoms, as the engine is not powerful enough to wind up wire, shot, and all.—Baltimore Sun.