The record-union. [volume] (Sacramento, Calif.) 1891-1903, 1899-08-11
Science and
3 Discovery.

server looks into space his line of sight
Is intercepted by a multitude of par
tlcies of dust floating in the air. The
reason these particles appear to be blue
Is tnat they reflect to the eye the blue
rays, against which they form an ef-
1ectlve barrier, while the red or coarser-
waved rays pass on. That the dust re,
meets back only the blue rays is due to
thelr microscopic size. The finer the
Just, the purer is the blue which 10
rejected or scattered. The bluest skies,
therefore, are seen in places where the
Gust particles are smallest; the blue of
the Sky as viewed from the tops o;
mountains is deeper and purer than
mat seen from a lower altitude This
IS due to the fact that the air is very
rare at great nights and can only sus-
tain the finer particles of dust, while
Inc coarSer particles abound in the low
er levels. The intensity of the blue sky
Tor which Italy is noted is not OWNS
TO the existence of finer dust than in
northern countries. but to the fact that
In the northern ATTITUDES, in conse-
quence of the greater GOODNESS of the
air, the vapor more readily condenseS
upon the dust particles. These particles
thus become larger and less effective
in turning back the blue rays alone. 1t
follows that other rays are rendered,
and a. grayish effect is produced. When
the sky forms a background for white
cumulus clouds, it appears to be bluer
by thecontrast than it otherwise would,
and after a shower when the lower
stratum of air washed of its coarse dust
particles, the result is deeper and
purer blue. The reason the reds are
prominent at sunset is that then the
dust particles are between the sun and
the observer, and the blues are reflected
away from him, while the reds pass
unobstructed to his eye.
London Telegraph: The report of the
Challenger expedition. a copy of which
has just been presented to DIR. Nansen
by his friends and admirers in England,
is one of the most remarkable publica-
lions ever issued, though, unless great
advance has been made since the last
report of her majesty's stationery office.
1t can hardly be said to be financially
one of the most successful. The report
shows that the office expended on print,
ing, paper. photography, binding, etc..
nearly t40, 600, and that in one way and
another this enterprise has cost over
tSS, 600. The work is bound up in
forty-seven large quarto volumes, con-
tanning q, $50 pages of letterpress, and
2,662 photographic and chromo-litho-
graphic plates. According 70 the latest
account the sales of the work, which
had cost fSS, 900. had amounted to
something under f1S.000. That sta
tionery office report. however, though
it is the latest to be had. is dated so
far back as 1890, and business may
have looked up a little since then. At
all events, here is one more copy gonG
Off
The Forum: When a man of ordinary
business experience is met by the state,
ment, that liquid air can be used TO
drive an engine, and that three gallons
of liquid air so used will produce ten
gallons of liquid air. he is incredulous,
and says, THAT is perpetual motion"
But when he is told. and truthfully told
that the new proposition is not 20 Greats
something out of nothing, but merely
to use a small part of the boundless
stores of energy which really exist in
the air and earth and water about US,
he is likely to be puzzled, if not con-
WINGED. He may ask whether this new
thing is any more unlikely than the
telegraph or the telephone or the Roen-
tgen rays seemed at first. To this ques-
ton there is a plain answer: The va,
rious wonders just named were not,
even at first, in opposition to any ac-
cepted scientific principle. They added
few pages to the books of science;
but they did not require the erasure of
a page already included therein. The
marvel of the telephone. for example,
lay not in the revolution of our ideas
as to electricity and magnetism, but
rather in the revelation of unsupported
sensibility of the human ear to slight
impressions.
That many interesting facts have
been discovered by the study of liquid
air is obvious; that important uses will
be found for this article is probable;
but that liquid air. taking energy from
objects at the ordinary temperature,
about us, can permanently replace the
usual agencies for the performance of
work, is proposition against which
can be set one of the most firmly es-
tablished principles of physical science
a principle upon which is based a larga
part of all that has been written dur
ing the last fifty years concerning the
relation of heat to other forms of en-
ergy.
London Globe: 1t has long beer
known that climate alone is not suffi-
cient to account for a colored people.
Dark skins are by no means confined
to the tropics; they are to be found in
races even beyond the temperate zone
This diversity according IN q writer i'm
one of the American magazines, can
only be accounted for by considering the
different modes of life that have acted
Tor centuries upon the various classes
and castles of the country The coolie
who works in the fields with a strip
of cotton cloth about his loins is very
dark; the merchant and trader who
never go abroad without being thor
oughly clothed are many degrees fair
er. 1t is said that a colony of Jews
on the west coast of India has been
established for nearly eighteen
centuries; but because they have not
followed the habits of the people as re-
CARDS clothing, they remain to this day
a white people. On the other hand
the Aryan populations of India and
Persia, originally fair people, by
adopting the customs of those coun-
tries, have become, in great measure,
q colored race. Accordingly, it is ar
gued that the steady march of nature
is toward the evolution of fair people
all over the world. The layer of dark
pigment beneath the cuticle prevents
the skin from blistering, and, when
proper clothing renders this safeguard
unnecessary nature diSpenses with it