The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1869-11-13
SCIENTIFIC.

OBSTRUCTI0Ne.-DaVlu hlttenhOuSe, Tue
celebrated astronomer, who was ski,lful in
measuring the size and determining the po-
sition of the heavenly bodies, found that
thread Of ordinary sewing silk drawn across
the glass Of his telescope would completely
conceal star. The finest fibre of silk would
hide distant star for several seconds. So
the smallest speck Of prejudice or the finest
thread of worldly policy or ambition drawn
across the lens Of the mind obstructs the
light Of divinest truth and hides half the
glory of the heavens. To see the spiritual
world we must keep the passions, cares and
loves Of the earth from the eye OF the soul,
as the astronomer wipes the steam and dust
from his glass
A RATo Of light travels II, 900, 900 miles per
minute Astronomers tell US that some Of
some Of the stars are so distant rs to require
for q ray Of light to reach US 2, 900, 900 years.
THERE are 43O species Of humming birds,
and they are found only on the western con-
tinent.
TnE London Spectator, speaking Of tidal
waves, has the following very interesting
statement
"Recently, for example, when Mr.. Adams
had published his proof that the moons mo.
ton ID gradually becoming accelerated in a
way IN which the lunar theory cannot &C
count for, N. Delaney, d leading French
astronomer, endeavored 10 prove that il
reality il is the earth's rotation which is d.
minishing instead Of the the moons motion
being increasing. He thought the tidal
wave, continually checked by the earth's
I friction as it travels against the direction Of
/ her rotation, would act as a sort OF break
since its friction must, in turn, check the
earth. And in discussing this matter he
took rs his fundamental axiom the law Of
/ tidal motion commonly given in our books
, Of geography and astronomy. This present
| " called up the Astronomer Royal who gave
very clear and convincing demonstration
! that there would always be low water under
/ the moon if there were no friction.
"But this is not all, nor is II even the
! most remarkable part Of the case. Eminent
as the Astronomer Royal deservedy is, and
especially skillfull as we know him to be in
questions such as the one we are consider
ing, vet if be were S0Ius contra mundum we
nigh readily believe that there was some
flaw in his reasoning, since, as every one
knows, the mos. eminent mathematicians
have sometimes misconceived the bearings
of perplexlng problem.
"But, as Mr.. Airy himself pointed out,
I Newton and Lapace were both with him !
How IS il that the views Of Newton and
Laplace, admittedly the very highest au-
! thorities which could be quoted, have found
no place in our treatises on astronomy !?
Their views have never been disproved. Ia
fact, as we have seen, one Of the most emf
nent Of our mathemalicIans, il re-examining
III, no nfna fO nrooiopiv iha
conclusion. Can il be thar the explanation
actually given is Preferred on account OF its
greater simplicity ?"
A NEW MODE OF RE-SHARPENING FILEs.-
A very interesting and economical process
has been exhibited before the SOcietie En-
couragsment Of Paris, by NJ. WeIdermann.
Well-Worn files are first carefully cleaned by
means Of hot water and soda they are then
placed in connection with the positive pole
of . battery, in a bath composed OF forty
parts OF sulphurIc acid, eighty parts OF nitric
acid, and q thousand parts of water. The
negative Lole is composed Of copper splr al
surrounding the files, but not touching them,
the COOL terminates In q wire, which rises
toward she surface. Tnis arrangement is
the result of practical experience. When
the files have been ten minutes en- the bath
they are taken out, washed aud dtied, when
the whole Of the holloWs will b. fOund to
have been attacked in a very sensible man
ner but should the effect not be sufficient,
they are replaced for the SAM period as be-
fore. Two operations are sometimes neces-
sary, but rarely more. The files thus acted
upon are to all appearances like new ones,
md are said to be good for sixty hours work.
NJ. WerdeTmann employs twelve medium
Bunsen elements tor his batteries.