Page:Popular Science Monthly Volume 43.djvu/469

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
469
PROTECTION FROM LIGHTNING.

purpose of only academies of sciences. But there are in Germany only three, at most four such academies, and they are far from sufficient to assure general progress over all the wide fields of science. A part of their function has thus fallen upon the universities, and they have performed it valiantly, sometimes gloriously. This is the reason why German university teachers demand more time than is required for the teaching in itself.

The universities have also an important function in the second direction, as I have said, in the training of new investigators and teachers. This is a very near duty, for only thus can that indispensable constituent of the teaching body, the position of privat docent, the nursery for future professors, be maintained and reproduced. Therefore, we should begin early to train independent workers from among the students.—Translated for The Popular Science Monthly.

 

PROTECTION FROM LIGHTNING.
By ALEXANDER McADIE.

DURING the year 1801 two hundred and five lives were lost (that we know of) in the United States, east of the Rocky Mountains, directly through the action of lightning. How many were lost indirectly, and how many cases there were of shattered health and more or less permanent injury, we can only surmise. The financial loss due directly to lightning was certainly not below one and a half million dollars. To get at something like a commercial estimate of the damage done by lightning in the past few years, in this country, I have made use of the Chronicle Fire Tables for the six years 1885-1890, and find that some twenty-two hundred and twenty-three fires, or 1·3 per cent of the whole number, were caused by lightning, and the total loss was $3,386,826, or 1·25 per cent of the whole amount lost by fire. During 1892 we have a record of two hundred and ninety-two lives lost. The damage may be estimated at as high a figure as in 1891. These losses are the more appalling when we recall that the year is virtually less than six months. Over ninety-five per cent of the casualties due to lightning occur between the months of April and September. It is therefore qutie pertinent at this time to discuss the question whether or not we are able to protect ourselves from lightning. Some five years ago the question would have been answered readily and with all sincerity, "Yes, a good electrical connection with the earth—a stout, continuous copper rod, for example—will suffice." To-day no such answer can pass unchallenged, for reasons which we shall see.

In 1888, after years of dispute, we had just settled down to the