VALUABLE NAUTICAL INVENTION.

Pelorus Guardian and Miners' Advocate., Volume 20, Issue 67, 24 August 1909, Page 5

VALUABLE NAUTICAL INVENTION.

’ Captain H. A. Gadsen, a retired ', officer of the mercantile marine, of American birth, now living in London, has invented a most ingenious aid to ocean travel, and magnanimously made a present of his ideas for the benefit of all who “go down to the sea in ships.” to the Bureau of Navigation to the United States. Captain Gadsen’s invention is as, important relatively as the sextant itself. The Japanese navy used it in the war with Russia, and to its employment the commanders of eight ships ascribed in a large measure their ability to surprise the enemy. Divested of its technical nomenclature, the invention, which is called the "spanner horizon," is intended to correct a false horizon, which the navigator dreads almost as much as he does the uncharted sunken rock, for he may be carried many miles out of his course, and not infrequently to a dangerous ambush, in the pathless lane he is following. Secure in the belief that his "sights are good,” which is the nautical way of saying that the safety signals are set, the mariner stands boldly on his course, only to find that he is several miles out of his reckoning, and has made a bad landfall.

The spanner horizon is so called because it exactly spans the periphery of the sun’s image reflected on the horizon glass of a sextant when day observations are taken. It carries a central wire for night work on which a star, a light ashore or afloat, or other small object may be brought in line, On the darkest nights the altitudes of the stars may he taken with the spanner. In the daytime, when the horizon is obscured and the limbs of the sun are brought between the legs of the instrument, the altitude of the sun's centre is obtained, and the true horizon is established. Captain Gadsen would rather know that 100 ships had laid a true course and avoided danger with the aid of his spanner horizon than receive 100,000 guineas. He deserves the heartfelt thanks of every one.