Thus the efficiency of the rods in actually preventing lightning strokes appears to have been about ninety per cent. It may be fairly assumed that a large part of the damage done to the rodded buildings occurred in cases where the rods were improperly installed or in poor condition.
Five companies, with over 18,000 buildings insured, of which more than fifty per cent were rodded, reported that they had never had a building burned or even materially damaged by lightning that was equipped with a lightning rod; their records covering periods ranging from thirteen to twenty-five years.
Another important fact brought out by Professor Smith’s figures is that when a rodded building is struck by lightning and damaged but not burned down, the average damage is much less than in an unrodded building, viz., ten dollars in the former and twenty-two hundred dollars in the latter.
Boy Attempts to Fly; Falls.
John Mitchell, aged fourteen, living in the Mount Vernon Road below Evansville, Ind., attempted to rival the birds, and came to grief, with a broken arm. Mitchell made a girder and wings after a pattern in a boy’s book which he bought at a local store.
He attempted to glide from the loft of the stable to the ground. The girders were not strong and the wings collapsed. Mitchell fell to the ground and his left arm was broken near the elbow and he suffered slight internal injuries.
Sharpening Stones; Their Various Uses.
Not many people realize that there is a special sort of whetstone for nearly every purpose. The proper sharpening stones for each different use are exhibited in the National Museum at Washington, D. C., and there are hundreds of them.
The hard, white, compact sandstone found near Hot Springs, Ark., are among the best whetstones known, equaling, if not surpassing, the Turkey stone, which for years has been considered one of the best.
The hard, flintlike stone should be used only to sharpen instruments made of the very best steel, requiring very[Pg 66] keen edges and points such as those used by surgeons, dentists, and jewelers. Other grades, although composed of the same ingredients, are more porous, the sand grains are not as close together, and a rougher edge is given to the sharpened tool. Because of their more porous nature, these stones cut faster, proving suitable for the finer-edged tools and for honing razors.