MAN-MADE LIGHTNING.

Auckland Star, Volume LXIX, Issue 209, 5 September 1938, Page 8

MAN-MADE LIGHTNING.

STRIKES AT WILL.

Tn a high-teneion laboratory. Dr. Bellaschi, Westinghouse research engineer, played with artificial lightning strokes of 3,000,000 volte; he split poles, as if with some invisible, gigantic axe. The laboratory was established to discover what happens when natural lightning strikes any part of a central power station system. Watching lightning from afar, science did a good deal of guessing. Eventually engineers decided to make their own lightning, and to control the conditions under which it manifested itself. Dr. Bellaschi has; been doing thie for the last five years— making and loosening artificial lightning strokes. The total number of "hite" in that time exceeds those made by real lightning on all the power systems of the United States. If these strokes were concentrated in a single "shot," there would be enough energy to light momentarily 333,000,000 ordinary 60-watt house lamps, or more than all the household lamps that ■are in operation at any one time in the -world. In his three-etorey* laboratory are 36 banks of condensers, each charged with 100,000 volte of direct current, with a combined output of 3,600,000 volts, comparable to the high applied voltage rise of a lightning stroke after it has hit a power line or a tree. Eight additional 'banks, of eight condensers each, represent so many cubic fe«« of a thunder cloud. When all the condensers act together they produce 150.000 amperes of current for 200,000.000 th« of a eeoond, which ie unusually long for a flash of lightning. It ia a dramatic moment before the manmade strokes begin to fall and split beanie as thick as telegraph poles. Orders are shouted. Lights- are dimmed, the better to see the coming flash. "It takes half a minute to charge the condenser," Dr. Bellaschi explains. "The etorm is brewing. The process is much like Nature's, but much more rapid. By continually bombarding electrical apparatus and equipment with the man-made lightning strokes, it has been discovered that the averages stroke consists of a core about the size of a man's finger, which, upon completion of the discharge, explodes into a column of spongelike fire, about four inches in diameter. It is this explosion that gives rise to the thunder. In thie core, pressures are developed up to 20.000 pounds to the square inch, when the discharge is confined. This explains why trees are split and killed. The core has a tempera- ' ture of about 14,000 deirreee. Centigrade—hot enough to vaporise everything on the earth if it were sustained."