Evening Republican, Volume 18, Number 93, Rensselaer, Jasper County, 18 April 1914 — TAKING VOLTAGE OF CURRENT [ARTICLE]

TAKING VOLTAGE OF CURRENT

Electricians Experimenting to Determine How Far the Spark Can Jump.

By measuring how far an electric current can jump through the air from one piece of metal to another electricians can determine the voltage of a current; and it is by setting a current to making broad jumps and then scoring the feat with a tape measure that the very high voltages used nowadays are ordinarily measured. But the judges of these athletic feats have recently determined that the electricity jumps much more surely from some sparks than from others, just as a man Is not likely to jump so well from a mud spot as from firm ground.- .... . Spark gaps, as these, jump measures are called because of the great electric spark that jumps, across the gap. have been made of needlepoints, says the Saturday Evening Post Now it

has been found that if metal spheres are used, and the electricity made to jump from one to the other, the result is more accurate; and sphere spark gaps are replacing the needlepoint jumps. Even with spheres to jump from the athletic electricity is not entirely satisfied unless each sphere is as big in dameter as the jump the current expected to make. With such spheres the spark of a current of 500,000 voltage will break down when the spheres are a little more than 15 inches apart