Gleanings From the World of Science

Notes Gathered From All Parts of the World

CURIOUS AND USEFUL

Popular Information on a Great Variety of Topics Interesting to the Student and Useful in the Practical Affairs of Life.

Prepared for the Democrat and Chronicle

The mysterious region to which Tesla introduced us in 1891, an electrostatic field of weird and startling effects, is being diligently explored. The lack of necessity for special apparatus brings the experiments within reach of many physicists, Tesla’s simple method of producing alternating currents of great frequency being to connect the secondary terminals of a high tension coil with the internal armatures of a Leyden jar, which discharges itself disruptively, the disruptive discharge yielding the desired current. Details have been greatly varied and improved. In a recent striking exhibition in Paris, M. Radiguet connected a rheostat, vibrator, induction coil, D’Arsonval oscillator and Oudin resonator, the rheostat being placed directly upon a 110-volt circuit. The coil, giving a 22-inch spark, and condensers of variable capacity, insulated in paraffine. The induced wires were connected with the armatures of a Leyden jar, this being D’Arsonval’s arrangement for producing alternating currents of great frequency, and the external armatures of the jar were connected with the Oudin resonator. The latter was formed of a solenoid of 195 feet of 1-10-inch uninsulated copper wire wound on a cylinder of paraffined wood. The contacts were fixed at the opposite sides of the upright cylinder, one a little higher than the other, and a tangent screw changed the number of spirals in each of the two parts of the solenoid, the lower part of which produced the oscillations of great frequency, while at the upper part were the currents of great frequency and very high tension. This apparatus was a great success. The resonator created all round it, within a radius of 6 1-2 feet, a very intense alternating electrostatic field, in which Geissler or Crookes tubes became luminous when simply held in the hand, a rotating iron wire became a cord covered with tufts of flame, the ribs of an umbrella glowed brightly, and tufts of violet light six or eight inches long stood out upon the hands. A theater dancer carrying mysteriously-lighted objects will be among the first displays of these wonders to the general public.