The Cincinnati daily star. [volume] ([Cincinnati, Ohio]) 1875-1880, 1878-07-20
SCIENTIFIC.

itself in keeping cars tolerably well ventil-
ated in summer, so fer as the requisite
supply of fresh air is concerned, for an
abundance of it can be introduced through
open doors and windows, and by the ordi-
nary roof entilators-sufficient, at least,
to disinfect or replace that which has been
contaminated by breathing. In cold
weather, however, the conditions are very
much changed. Carbonic acid gas and the
organic poisons, exhaled with the breath
or discharged from the pores of the skin,
ore present, and the desideratum is to get
rid of them in a quiet, automatic way.
But this, at such s.ason, can only be ac-
complisled by q constant process of ex-
pulsion, and the introduction of a corres-
ponding supply of warm ani uncontami-
mated air. car full Of bad air will not 60
out unless an opportunity is afforded, and
portion of it will remain even then unless
forced-and the necessary force or motive
power must be derived from the speed of
the train or an inhowing current induced
by rarefaction, or both combined.
| M. HE1MHoLTz, in paper on visual ap-
paratus, expresses the opinion that, con-
sidering the extreme care expended on the
calculation and execution of lenses for tele-
scopes and Photographic camera, it is really
matter of surprise that with the lenses OF
the microscope are SO much more
difficult to construct according to the pre-
scribed dimensions and which have SO large
an aperture-aberration makes itself SO lit
tie felt. While, therefore, theory has un-
doubtedly contributed largely to the perfec-
ton of lenses for telescopes and cameras,
it has, says NJ. Helmholtz, hitherto done
little, AMI indeed, can do comparatively
little, for the perfection of microscopical
objectives. Almost all the markers of
such lenses depend upon acquired skill ia
the use of certain tests, that is, the arti-
fetal star, as indicating the necessary
changes, in laboring toward perfection
and very seldom, it is believed, has such
perfection been the result of rigid Sd-
herence to curves, thickness, apertures,
&c, previously indicated by theory; in not
a few cases such presumed improvements
have resulted in entire failure.
A WRITER in the London Times points
out that the number of satellites of the
heavenly bodies probably varies in geomet-
rical progression, of which the ratio is
two for the great planets from the earth.
Thus, the latter has but one moon, Mars
twice as many--two; Jupiter twice as
many as Mars - FOUR Saturn twice as
many as Jupiter-eight 1t may be sup
posed, according to this, that Uranus has
twice as many moons as Saturn, namely,
sixteen, and consequently that Neptune has
thirty-two-it being impossible, however,
to see these, owing to the immensity of
distance from the earth, In this connec-
tion it is also stated that M. Petit of the
Observatory of Toulouse, advocates the ex-
istence of second satellite of the moon,
which he believes he has seon several
times If the diameter OF the satellites of
Mars is as small as reported, such bodies
could easily revolye round the moon un-
noticed by astronomers on the earth and
the opinion is also expressed that their
presence might account for some of the
known irregularities in the moons mo-
ton.
THE following is an improved German
method of fulling woollen goods, which is
said to require but few hours, and to
leave the wool very soft, While it does not
attack the color. The plan is simply to
replace the fuller's earth by suint, the lat
ter being obtained rs follows. A wood n
vessel is filled with raw, unsecured wool,
on which water is pumped from another
vessel, and allowed to remain upon it soma
three hours. 1t is then all pumped back
into the second vessel, and agaM over the
wool in the first vessel, and allowed to re-
main on it for the space of two hours. The
. operation is repeated several times, ac-
cording to the quantity of sufnt in the
. WOOl; bLo lGLLCE ID tHGu IGluOVGu ana
thoroughly freed from water, and fresh
portion OF wool intro luced and treated in
similar manner, until the water is sutl-
cieplly saturated with saint, when it is
drawn off and preserved for use. The cloth
that is fulled VITA the necessary quantity
of this liquid, in the machine, and then
washed in thorough manner, is said to
, be found perfect.
AN attachment to the ordinary spring
eye glasses, by which they can, at will, oe
transformed into spectacles and as quickly
: relieved from the attachment, is among
the most recent and useful devices that
have been brought forward. 1t was Or.
Cid, the well-known Paris surgeon, who
found that the spring eye glasses injuriously
! compressed the arteries by which the nose
4 is nourished, making that organ long and