taken
up while the train is running. The principal advantages claimed for
the railway are: The absence of vibration and of side rolling motion;
the pleasure of traveling is comparable to that of sleighing over a
surface of ice, there is no noise, and what is important in town
railways, no smoke; no dust is caused by the motion of the train during
the journey. It is not easy for the carriages to be thrown from the
rails, since any body getting on the rail is easily thrown off by the
shoe, and will not be liable to get underneath, as is the case with
wheels; the train can be stopped almost instantly, very smoothly, and
without shock. Very high speed can be attained; with water at a
pressure of 10 kilogrammes, a speed of 140 kilometers per hour can be
attained; great facility in climbing up inclines and turning round the
curves; as fixed engines are employed to obtain the pressure, there is
great economy in the use of coal and construction of boilers, and
there is a total absence of the expense of lubrication. It is,
however, difficult to see how the railway is to work during a long and
severe frost. We hope to give further illustrations at an early date
of this remarkable invention.--_Industries._

* * * * *

QUARTZ FIBERS.[1]

[Footnote 1: Lecture delivered at the Royal Institution, on
Friday, June 14, by Mr. C. V. Boys, F.R.S.--_Nature._]

In almost all investigations which the physicist carries out in the
laboratory, he has to deal with and to measure with accuracy those
subtile and to our senses inappreciable forces to which the so-called
laws of nature give rise. Whether he is observing by an electrometer
the behavior of electricity at rest or by a galvanometer the action of
electricity in motion, whether in the tube of Crookes he is
investigating the power of radiant matter, or with the famous
experiment of Cavendish he is finding the mass of the earth--in these
and in a host of other cases he is bound to measure with certainty and
accuracy forces so small that in no ordinary way could their existence
be detected, while disturbing causes which might seem to be of no
particular consequence must be eliminated if his experiments are to
have any value. It is not too much to say that the very existence of
the physicist depends upon the power which he possesses of producing
at will and by artificial means forces against which he balances those
that he wishes to measure.