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Show FOREWARNING OF THE ICEBERG. One of the magazines tells of the invention of H. T. Barnes, a pro. fessor of McGIll University, intended to detect icebergs in time to allow ships in danger to avoid collision. The Instrument Is known as a micro-thermometer, micro-thermometer, which measures the thousandth part of a degree of tern-perature, tern-perature, and consists of a galvanometer, galvano-meter, -which measures the difficulty electricity encounters in passing through an iron wird, the warmer the wire the easier the current flowa I through the metal, and this varies and can be Indicated down to a millionth mil-lionth part of a single degree change. I Soon after the Titanic disaster the statement was made that there -was no appreciable change in the temperature tem-perature of the ocean at the approach ap-proach of an icebrg, but this error was due to the fact that the variation could not bo Indicated by any instrument instru-ment then known. Quoting from the source of our in-formation: in-formation: ';As heretofore carrfed, on, the taking of water temperature aboard steamships was largely a perfunctory and valueless operation. A quartermaster quarter-master would lower a bucket "by a rope, draw up a buckotful of water, take its temperature with an ordinary household thermometer, and record tho reading. Tho scale was divided Into degrees, and for fractions of a degree it was guesswork entirely. By the time the reading reached the ship's officers, the place where the reading was taken was many miles astern. After the Titanic disaster,-Professor disaster,-Professor Barnes devised' tho micro-thermometer. micro-thermometer. With this in action, Professor Barnes has a constantly varying va-rying change in the resistance of tho iron wire to the passago of the electric elec-tric current. He keeps the coll of wire down in the cold water at tho ship's Intake, and every variation of temperature is sent up to tho officers quarters, where a pen makes a continuous con-tinuous record on a prepared chart showing tho constant rise and fall of temperature. One of these micro thermometers is Installed at tho botf and another at the stern, and it Is easy thus to tell whether the ship Is head ed toward cold water or toward warn water. Night and day tho little in strument floats on through the sen telographlng the temperature It en counters to tho officers and tracing tho ups and downs of heat and cold through every moment of tho twen ty-four hours. Not only does It herald the approach of an icebrg, but tho approach to shore as well. It shows constantly just what kind of water the ship ib passing through, and never loafs on Its job a single second. This little Instrument has revealed other facts and has been put to other uses. It shows that during the winter months the St Lawrence river uevtjr varies enough from tho freezing point for the change to bo caught by ordinary ordi-nary ship thermometers. Yet the change of a few thousandths of a degree de-gree produces enormous physical effect ef-fect The character of a river muy be changed overnight by such a slight fluctuation of temperature and the wheels of the largest hydro-electric station stopped by it. As a result of the revelations of this little instrument, instru-ment, it now is possible for big plants to recognize these changes in time to apply a little artificial heat around the gates and wheels, and thus to prevent a closing down of their machinery." ma-chinery." . nn |