170 
POPULAR SCIENCE NEWS. 
[November, 1890. 
genitors of the modern inhabitants of Europe, 
originated in the highlands of Central Asia, 
thence emigrating in successive waves to the 
countries Iving to the westward. Since the 
discovery of the connection between the lan- 
guage of the Finns and the ancient Sanskrit 
tongue, this belief has been greatly shaken, 
and numerous theories have been advanced 
concerning the origin of our race, the last 
one being that our "old homestead" was sit- 
uated in the southern part of what is now 
Russia. The question is a difficult one to 
settle, and it seems as if we inust finally 
admit that the beginning of our race was so 
far back in the pre-historic ages that it is 
impossible to discover its source. We know 
that man has existed for tens, if not hundreds 
of thousands of years, — a period compared 
with which our oldest records are but as 
yesterday. Constant movements of popula- 
tion must have been going on during the 
greater part of that time, and, instead of 
accepting the ancient Aryans as the founders 
of our race, we should take pride in possess- 
ing a pedigree so long that its beginning is 
lost in the fogs and mists which accompanied 
the close of the glacial period. 
THE MEASUREMENT OF MINUTE 
FORCES. 
With the increased attention now being 
given to the study of physics, the measure- 
ment of the most minute natural forces has 
become an important matter. The weakest 
currents of electricity — even those developed 
by the beating of the heart — can be trans- 
formed into mechanical movements, and their 
existence made evident, to the senses. Even 
the infinitesimal difference in the force of 
attraction of gravitation between an empty 
hall and one with an audience assembled 
therein, can be made perfectly visible to the 
audience itself 
The general principle upon which all these 
measurements depend is that of the torsion^ 
or twisting, of a fine thread or fibre, to which 
a small mirror is suspended. A ray of light 
is thrown upon the mirror, which reflects it 
upon a screen. Any force, therefore, which 
moves the mirror in the slightest, is at once 
shown in a greatly magnified degree by the 
movement of the spot of light upon the 
screen. It is like applying power to the 
short end of a lever, only in such a case our 
lever is a ray of light, without inertia or 
weight, and moving without friction. 
It is evident that the finer the thread by 
whiclr the mirror is suspended, the more 
sensitive it will be to the action of forces 
tending to twist it, and a perfect means 
of suspension for the mirror has long been 
sought after by physicists. Fine hairs were 
at first used, but even they were too large, 
and offered too much resistance to the forces 
under investigation. Fine metallic wires were 
tried, and the much finer thread spun by the 
silkworm. Glass was drawn out into micro- 
scopically fine threads, which served a good 
purpose, the principal objection being their 
somewhat imperfect elasticity, which pre- 
vented them when once twisted from return- 
ing to their original position. A comparison 
of these different fibres with the quartz 
threads referred to below is shown in the 
engraving. They are, of course, greatly 
magnified, each of the smaller divisions on 
the scale representing a hundredth of a milli- 
metre, or 1-3500 of an inch. 
In the threads of quartz, first produced by 
Mr. Vernon Boys, we have a substance 
which is not only perfectly elastic, but is 
unaffected by atmospheric changes, and is 
strong enough to support a considerable 
weight, while the threads can be made much 
finer than anything formerly produced. They 
are made by shooting from a little bow an 
arrow consisting of a straw, which has been 
previously attached to a small cylinder of 
quartz, one end of which is fused by the oxy- 
hydrogen blowpipe just before shooting off 
the arrow. As tlie arrow flies through the 
air it draws out a thread of quartz of an 
inconceivable fineness, and so light that it 
will float in the air. Some of these fibres 
have been estimated to be less than one mil- 
lionth of an inch in diameter, or, to give an 
idea of their fineness, if a cubic inch of quartz 
was drawn out into such a thread, it would 
reach 65S times around the world. 
The size of thread, however, most used in 
actual work is about 1-10,000 of an inch in 
diameter, and is ten thousand times more 
sensitive to a force of torsion than the finest 
glass threads ever made. With such a quartz 
threatl, Mr. Boys has shown directly to a 
large audience the attraction of gravitation 
exerted by spheres of lead of two pounds in 
weight upon smaller spheres weighing fifteen 
grains. This attractive force is calculated to 
be less than a thirteen millionth of a grain, 
and it is believed that it will be possible to 
measure a force two thousand times more 
feeble than this. 
These figures, although incomprehensible, 
are real, and, like the wave lengths of light, 
or the chemical molecules and atoms, stand 
for actual and definite mathematical relations. 
Their contrast with the magnitudes of the 
celestial bodies and spaces, which are the 
study of the astronomer, is most marked, and 
leads us noH: only to admiration and wonder at 
the construction of the universe, but also at 
the capabilities of the human mind which 
can conceive, and even, perhaps, imperfectly 
comprehend, such extreme manifestations 
of weight, mass, and energy. 
THE HIGHEST SCIENTIFIC STATION 
IN EUROPE. 
The accompanying illustration (from La 
Nature) gives a view of a cabin, erected 
during the past summer, at a point near the 
summit of Mont Blanc, at an elevation of 
13,300 feet above the sea. It is divided into 
two rooms, one of which is intended for the 
use of parties' on their way to the summit, 
while the other is a well-equipped meteoro- 
logical observatory, supplied entirely with 
self-registering instruments, which only need 
attention once in fifteen days ; and it is 
intended to visit the observatory at such an 
interval during the summer months. Of 
course, in the winter the cabin is inaccessible 
to everyone. 
In point of altitude, the Mont Blanc 
observatory is slightly less than that of the 
signal station on Pike's Peak, Colorado, 
(14,147 feet), and the latter possesses the 
great advantage of being occupied all the 
year round. Owing to the favorable climatic 
conditions, the ascent of Pike's Peak is ex- 
tremely safe and easy, and a matter of daily 
occurrence, while, ^s is well known, only the 
most expert mountaineers can gain the sum- 
mit of Mont Blanc, and even then at a con- 
siderable risk of danger to life or limb. 
This cabin was erected under the auspices of 
M. J. Vali-ot, of the French Alpine Club, 
and was accomplished in the face of almost 
insurmountable difficulties. Everything con- 
nected with the building had to be carried on 
the backs of men from the village of Chamo- 
nix in the valley below. The boards and 
other materials for the construction of the 
cabin made up one hundred and twelve 
loads, while the furniture, instruments, etc., 
required ninety additional journeys to trans- 
port up the mountain. Six weeks were 
required to deliver the materials, and on 
the 25th of July M. Vallot, with five car- 
penters and two guides, went into camp in 
the snow on the mountain and commenced 
work. 
Notwithstanding the great cold, satisfactory 
