Page:Popular Science Monthly Volume 24.djvu/298

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286
THE POPULAR SCIENCE MONTHLY.

as these are stuck into sockets all over a plate-iron floor, at just such a distance apart as will enable a wheat-sheaf to be comfortably spiked upon each tube. The floor, with its small forest of tubes, is laid, air-tight, upon a dwarf foundation wall of about two bricks high, with a partition down its center. The hot-blast is then blown into the closed space thus formed between the ground and the tube floor, and rises through the tubes into the sheaves just where they are wettest, viz., at the band. A simple shunting valve directs the hot air first under one half of the floor, and then under the other, so that, while the sheaves on one half are drying, the others may be lifted off and replaced with more wet sheaves."

 

Fogginess of Malaysian Ideas.—Mr. D. D. Daly, who has been engaged in surveys of the native states of the Malay Peninsula, says that the natives show an almost total lack of notions of definite points, and have only the vaguest ideas with reference to the determination of boundaries. "The boundary of our state," said one, "extends as far as the meeting of the fresh water, with the salt water of the river"; or, "If you wash your head before starting, it will not be dry before you reach the place"; or, "The boundary may be determined on the river, as far as the sound of a gun may be heard from this hill." The shot might be fired from a smooth-bore or from a twelve-pounder, or a gale of wind might carry the report farther than was contemplated. Such ambiguous phrases were calculated to mislead, but they were essentially Malaysian in their generality.

 

Electricity from Gas.—A German professor, Dr. Von Marx, has shown that more light can be obtained from a given quantity of gas by burning it in a gas-motor which drives a dynamo-machine, than by burning it in the ordinary burner. His estimate is based on the following calculations: A gas-motor will consume on the average thirty-seven cubic feet of gas per hour for each horse-power. An argand burner, giving a light equal to eighteen candles, will consume five and a half cubic feet per hour, so that the amount of light obtained by burning thirty-seven cubic feet of gas in an argand burner will equal one hundred and twenty candles. In the Swan system of electric lighting, the light obtained from each horse-power (or by burning thirty-seven cubic feet of gas) is stated to be equal to one hundred and fifty candles. The light obtained by the Edison lamp he gives as between one and two hundred candles. Mr. Lungren, in his paper in the September number of "The Popular Science Monthly," estimates that eight lamps can be maintained for each actual horse-power, and if we make each lamp equal eighteen candles, we have a total of one hundred and forty-four candles per horse-power, a gain of twenty per cent over the use of an argand burner. When the. Jablochkoff candle is used, the results are much higher, each horse-power yielding a light equivalent to four hundred and seventy-two candles; while other arc systems run four or five times as high. In showing that more light is obtained by burning thirty-seven feet of gas in a gas-motor than by burning it in an argand burner, Professor Von Marx does not prove that it would be economical to do so, for the margin, taken as twenty per cent, is not sufficient to cover the cost of converting gas into electricity, so to speak. That the latent energy pent up in illuminating gas should produce more light when converted into electricity, notwithstanding the loss at each stage of the operation, than when burned directly, is explained by the fact that the larger part of the energy of burning gas is manifest in the form of heat, the lesser part in the form of light. In electricity we have just the opposite conditions.

 

Transparent Points in Leaves.—M. Theodore Bokorny has published a prize essay in the University of Munich on the "Transparent Points in Leaves." These points, which are quite common in some plants, mark the places where a group of cells, containing resin or an ethereal oil, has been collected. One of the most familiar instances of this kind is that of the St.-John's-wort (Hypericum perforatum), in which mediæval superstition imagined a connection between the lucid spots and the wounds of Christ, and assigned a healing virtue to the plant. In other cases the points in question are caused by cells with a slimy coat-