MAGNETIC TESTS.

Lyttelton Times, Volume LXX, Issue 8668, 18 December 1888, Page 6

MAGNETIC TESTS.

(Flushing Journal .) Through a happy thought of Major W. E. King, the Commandant at the Willeth Point military post, the post now boasts one of the largest and strongest magnets in the world. This magnet has already been referred to in the Journal, and some of the more recent experiments of its power made cannot fail to be of interest to our readers, together with a short history of this wonderful instrument itself. How the magnet came to be made was in this manner Last December Major King happened to see two large 15in Dahlgren guns lying unused side by side on the dock. He conceived the idea that a magnet of enormous power could be constructed by means of these cannons with submarine cable wound about them. The experiment proved very successful. The magnet, which stands about ten feet from the ground, is eighteen feet long, and has eight miles of cable wound about the upper part of the guns. Some faint idea of its power may be conceived from the fact that'it takes a force of 25,000ib to pall off the armature.

The tests to demonstrate the enormous power of the magnet were made in the presence of a number of the officers of the United States Engineering Corps, and were highly successful. A crowbar which was applied to the magnet required the combined force of four strong men to tear tear it away. A handful of pins thrown in the opposite direction immediately flew back and attached themselves to the magnet. A seemingly impossible experiment was performed with some fifteeninch cannon balls. The balls were solid and as much as a strong man could lift, yet the magnet held several of them suspended in the air, one under the other. The most interesting experiment, and the one that was regarded with the greatest attention, the test made of an American non-magnetic watch. Eversince the great railroads of the country have compelled their employees to provide themselves with timepieces that would not he affected by the magnetism generated by the car trucks, there has been much speculation as to whether such a watch could be made, and a sharp rivalry has been going on between the American and Swiss manufacturers. The test was highly satisfactory, and once more proved that whenever a new invention was imperatively demanded, American genius could fully hold its own against the whole world. Major King’s magnet was so powerful that an ordinary watch was stopped stock still as soon as it came within three feet of it. Before the test was made there was quite a diversity of opinion among the experts present as to how far it would prove successful. Those who believed that a watch might be constructed that would resist magnetic influence under ordinary circumstances, were also of the opinion that when it was subjected to the most powerful magnet in the world the steel pinions would jar soon the working parts that the watch must necessarily stop. For ten minutes the watch was held in front of the magnet. It did not vary the hundredth part of a second. The man who held it said that he himself was conscious of the influence of the magnet. He could feel as he held the watch by the chain that some other power than his was keeping it suspended. The must amusing experiment was made with a sledge hammer. When one tried $o wield it in a direction opposite to the magnet he felt as though he were trying to hit a blow with a long feather in a gale of wind. There is nothing in the world that could take the conceit out of a strong man so much as this simple experiment. Another amazing test was made with a number of carpenter’s spikes. A spike was put lengthwise on the end of the magnet, then another spike was attached to the first, and so on until a line of them stood straight out from the magnet at least four feet iu length. Aside from their interest to science, the experiments were so novel and startling that they were entertaining even to those who were not interested in the wonderful developments of electricity.