The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1870-01-08
SCIENTIFIC.

COATING SHIP's BoTToMs.-An English
patent has recently been granted for the use
of paraffine as the basis of a compound for
coating ships, boats, and other surfaces, to
protect them from fouling, oxydation, etc.
A FRENcHMAN, Of Italian origin-Ferdi-
nand Tommasi-claims to have discovered
mode of employing the rising and falling
tides as a motive power. He will write a
pamphlet on the subject.
AN eminent physician says that the
white rubber used for nursing bottles and
inf'nt's toys is very poisonous, causing sore
mouth, skin eruption, decayed teeth, spinal
curvature, and death. In Europe the sale
Of it is prohibited by law.
SMALL-Pox.-A surgeon Of the British
army in China is reported to have discovered
an etfectual remedy for smallpox. The
treatment is as follows: When the Fremont
tory fever is at its height, and Just before
the eruption appears, the chest of the patient
is rubbed with croton oil and tartar emetic
ointment. This application, it is asserted,
causes the whole of the eruption to appear
on the chest to the relief Of the rest Of the
body. 1t also secures full and complete
eruption, and thus prevents the disease from
attacking the internal organs.
ENVELOPE MACHINEs.-In cutting en-.
velope blanks it has been most common to
use dies cutting large number simultan-
eously from pile Of many thicknesses Of
paper. A new machine operates on a diff
erent principle, and is thus described by an
English cotemporary =" A series of swing
ing shears are so applied as to cut out the
envelope blanks one at time by series Of
shearing cuts from one thickness, sheet, or
long strip of paper, so that there is little or
no waste except at the necessary cores re-
moved at the angles of the envelopes to al
low the flaps to lap in. Folding shears ar
ranged in this manner cut out enc blank
envelope at once, and the cutting edges re-
main in working order for considerable
time. When dull they can very readily
be ground.
GREAT TELESCOPES Now BEING MADE
MIR. NJ. De La Rue is having lens con.
structed Of thirteen inches in diameter, soon
to be in operation, from wi in the
hands Of SO skillful director, mLI may be
expected. Prof. Henry Draper, of America,
has very nearl ycompleted new silvered glass
reflector Of twenty eight inches diameter
(the largest of the kind yet constructed, ex-
cept one by FOucault). With this instru-
ment original negatives will be taken six
inches in diameter, with provision for ex-
tending them to nine and half inches if
desirable. Such pictures will, Of course,
contain an amount of detail not possible in
those taken with ordinary instruments
which vary from one to two inches in diam
eter, according to the size Of the telescope
Prof Draper expects thus to obtain photo
graphs of larger size and sustaining higher
magnifying power than any that have yet
been produced. The amount of advantageous
will not be limited by the ap-
pearance Of silver granulation, but will de-
pend wholly on the sharpness Of definition
obtained in the original picture. There is
now at Melbourne, in Australia, powerful
rejecting telescope four feet in diameter, Of
Cassegrain form, which will be supplied with
the necessary apparatus for photography, |
as well as for spetroscopic investigation. !
This derives its importance chiefly from the
fact that the work will be prosecuted in
rich fields Of the southern hemisphere. We
may look forward to important discoveries
with such means at our disposal.