£15 PER FLASH.

Auckland Star, Volume LXVII, Issue 206, 1 September 1936, Page 9

£15 PER FLASH.

COST OF LIGHTNING.

ELECTRICITY IN THE AIR.

WHAT HAPPENS IN STORMS,

Under present electric power charges, it would probably cost you something like £15 to buy an average lightning flash. This is according to the calculation of Dr. Wallace A. Macky, M.Sc., of Wellington, who, in the University College Hall last night, spoke of the fascinating and, to the layman at least, uncanny presence of electricity in the atmosphere. The address, under the auspices of the Auckland Institute, was illustrated with lantern slides.

"In an average storm," said Dr. Macky, "there can easily be a flash every ten seconds, and such a storm wastes energy at a rate of over 2,000,000 horsepower; When we consider that thei e are at any given instant some 1800 thunder storms over the earth we arrive at the huge figure of 3,600,000,000 horsepower, or 2,700,000,000 k.w., as the power being continually wasted in these storms. It is interesting to compare this power with the 10 k.w. of the new IYA; no wonder static often gets the better of a radio station." From Air to Earth. There was a current of electricity continually flowing into the earth from the air in fine weather, said Dr. Macky, and its value was found to be close to 1000 amps, for the entire surface of the globe. The major problem of atmospheric electricity was: Where did all this current come from? It was a problem by no means entirely solved. Measurements? of this "line-weather potential gradient," as it is known, had been made for several years, and it had been found not at all constant at any given place. There was a yearly and daily variation, and over the land there was an early-morning maximum resulting from the smoke - of fires being lit as the day's work began.

The interesting tiling about tlie daily variation was that it kept in step with the number of thunder storms .taking place on the globe. There were definite indications that the thunder storms were connected with tins current which flowed into the earth. A lightning flash, Dr. Macky went on, was merely a very lai'ge scale electric spark; Benjamin Franklin had .proved the identity by actually getting sparks from a wire attached to a kite which he flew underneath a thunder storm.

"I imagine that he was very lucky to survive to tell the story," added the speaker. "Since the advent of broadcasting, we are much more used to hearing lightning than seeing it, for the static which we' hear is nothing more than the electric impulses sent out by lightning flashes, sometimes near at hand and sometimes far away —and the further away the better, from the point of view of our wireless reception." "Fireball" Photograph. One of Dr. Macky's most int cresting pictures was a unique pliotogr.iph of "globe" lightning or a "fire-ball." Fireballs, he explained, were large glowing masses which from time to time had been reported in many strange fashions. Sometimes the size of a football, they had suddenly floated into a room glowing with a purplish light, and after wandering round to the terror of the occupants, they had disappeared up the chimney or exploded with a loud "bang!" leaving, it was often said, a smell of sulphur. Some time ago Professor Jensen, of Nebraska, engaged in photographing lightning, saw three large luminous balls appear about 200 yards away;, they fell slowly on to some telegraph lines, rolled along these for a short distance and then passed out of sight. He managed to photograph them before they disappeared, however. What these fireballs exactly are is still unknown.