Scientific American Supplement, No. 643 | Page 9

the
temperature back to 103 degrees, but when it is at 103 keep it there,
even if it occasionally requires two buckets of boiling water. To judge
of what may be required, let us suppose the operator looks at the
thermometer in the morning, and it is exactly 103 degrees. He estimates
that it will lose a little by night, and draws off half a bucket of water. At
night he finds it at 102. Knowing that it is on what we term "the down
grade," he applies a bucket and a half (always allowing for the night
being colder than the day). As stated, the sawdust will not allow the
drawer to 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.]
* * * * *

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.
* * * * *

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,