Scientific American Supplement, No. 643 | Page 9

become too cold, as it gives off heat to the drawer. And, as the sawdust absorbs, it is not easy to have the heat too high. One need not even look at the drawer until the proper times. No watching--the incubator regulates itself. If a lamp is used, too much heat may accumulate. The flame must be occasionally turned up or down, and the operator must remain at home and watch it, while during the third week he will easily cook his eggs.
The incubator can be made at home for so small a sum (about $5 for the tank, $1 for faucet, etc., with 116 feet of lumber) that it will cost but little to try it. A piece of glass can be placed in front of the egg drawer, if preferred. If the heat goes down to 90, or rises at times to 105, no harm is done. But it works well, and hatches, the proof being that hundreds are in use. I did not give the plan as a theory or an experiment. They are in practical use here, and work alongside of the more expensive ones, and have been in use for four years. To use a lamp attachment, all that is necessary is to have a No. 2 burner lamp with a riveted sheet-iron chimney, the chimney fitting over the flame, like an ordinary globe, and extending the chimney (using an elbow) through the tank from the rear, ending in front. It should be soldered at the tank. The heat from the lamp will then pass through the chimney and consequently warm the surrounding water.--_Rural New-Yorker._
[For description and illustrations of this incubator see SUPPLEMENT, No. 630.]
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THE PEAK OF TENERIFFE.
The Hon. Ralph Abercromby made a trip to the island of Teneriffe in October, 1887, for the purpose of making some electrical and meteorological observations, and now gives some of the results which he obtained, which may be summarized as follows: The electrical condition of the peak of Teneriffe was found to be the same as in every other part of the world. The potential was moderately positive, from 100 to 150 volts, at 5 ft. 5 in. from the ground, even at considerable altitudes; but the tension rose to 549 volts on the summit of the peak, 12,200 ft., and to 247 volts on the top of the rock of Gayga, 7,100 feet. A large number of halos were seen associated with local showers and cloud masses. The necessary ice dust appeared to be formed by rising currents. The shadow of the peak was seen projected against the sky at sunset. The idea of a southwest current flowing directly over the northeast trade was found to be erroneous. There was always a regular vertical succession of air currents in intermediate directions at different levels from the surface upward, so that the air was always circulating on a complicated screw system.
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ESTRADE'S HIGH SPEED LOCOMOTIVE.
We illustrate a very remarkable locomotive, which has been constructed from the designs of M. Estrade, a French engineer. This engine was exhibited last year in Paris. Although the engine was built, M. Estrade could not persuade any railway company to try it for him, and finally he applied to the French government, who have at last sanctioned the carrying out of experiments with it on one of the state railway lines. The engine is in all respects so opposed to English ideas that we have hitherto said nothing about it. As, however, it is going to be tried, an importance is given to it which it did not possess before; and, as a mechanical curiosity, we think it is worth the consideration of our readers.
In order that we may do M. Estrade no injustice, we reproduce here in a condensed form, and in English, the arguments in its favor contained in a paper written by M. Max de Nansouty, C.E., who brought M. Estrade's views before the French Institution of Civil Engineers, on May 21, 1886. M. Nansouty's paper has been prepared with much care, and contains a great deal of useful data quite apart from the Estrade engine. The paper in question is entitled "Memoire relatif au Materiel Roulant a Grand Vitesse," D.M. Estrade.
About thirty years ago, M. Estrade, formerly pupil of the Polytechnic School, invented rolling stock for high speed under especial conditions, and capable of leading to important results, more especially with regard to speed. Following step by step the progress made in the construction of railway stock, the inventor, from time to time, modified and improved his original plan, and finally, in 1884, arrived at the conception of a system entirely new in its fundamental principles and in its execution. A description of this system is the object of the memoir.
The great