Fair play., 1880-03-06
USEFUL AND SCIENTIFIC.

tory IN Germany turns out one thousand
pounds of grape-sugar day made from
old linen. The old linen, which is pure
vegetable tibrine, is treated with sui,
phuric acid and converted into dextrine
This is washed with lime-watcr, and
then treated with more acid, and almost
immediately it changes and crystallizes
into glucose-or grape-sugar-whichi is
highly valued in the making OF rich
preserves and jellies. The process is
said to be economical, and the sugar is
chemically the same as that found in the
grape. Why the product should be
objected to on the score of its origin Is
not clear, if one reflects that grapes are
nourished by materials more offensive
than old rags, and that there is prac-
tically no difference between Il trans.
formation in Natures laboratory and
one in the laboratory of the chemist
Still there is great outcry over the
German sugar-rag factory, and consid-
cradle danger of the enterprise being
stopped by the German Government.
\ VALUABLE FIBROUs PLANT-Pruf
S. Waterhouse, of the Washington Uni
| verslty, st. Louis, says: "The recen,
experiments of Mr.. Lefranc seem to
prove that the Abutilon avicenm con,
tains a valuable fiber for textile use
This plant abounds throughout the West,
and has with rapid spread and rank
luxuriance taken exclusive possession OF
whole fields. Its aggressive depravity
has earned for it the irreverent title OF
% DEVILS Plant But what has hereto.
fore been regarded as a noxius weed
may yet become an important addition
To our domestic fibers. Ii is already
worth s. Il ton in the market. Farmers
can judge for themselves whether thi.
price will afford margin of profit
! When the plant is raised in large guam
titles, and when factories, erected in the
neighborhood OF production, save the
cost Of distant transportation, the cult
vation Of this fiber will become more
remunerative. Next year extensive
trials will be made in the raising of the
"Devil's Plant" and it is the object OF
this note, through the courtesy of your
columns, To ask Western farmers to col
lect As large quantity of the seed As
possible, in order to facilitate expert
ments which may yet greatly rebound
| to their own interests
| THE VELOCITY Of SOUND. A memoir
is published by William W. jacques, in
! the .imericstn Jonraal Of Srience and Arts.
on the velocity of very loud sounds.
The author gives an account of expert
mentS, made at the United States Arsen-
al at Watertown, Mass, for the purpose
of obtaining automatic measurements
Of the velocity of sound near Il cannon.
behind the cannon-a SiX-pounder brass
tield-picce-hc placed, at distance of
10, 80, 30, 80, and 100 feet from It's
mouth, ingeniously constructed men,
branes, having an electrical connection
with Il chronograph capable of record
in@ .ooo0l of Il second. He found that
the velocity of the sound was
not greatest at the immediate
rear of the cannon, but ut some
distance from it, where it rose to a
maximum considerably above the or
dinary velocity, and then fell gradually
to about the velocity usually received. ="
When the cannon was turned ut right
angles TO the line of the series Of men,
branes the distance of the maximum
velocity of the sound came nearer the
cannon. From these facts the author
concludes that the velocity of sound is a
function of its intensity. and that the
experiments upon the velocity of sound
in which a cannon is used contain an
error, probably due to the bodily motion
of the air near the cannon. The employ
ment of 4 musical note of slow intensity
is, therefore, recommended to correctly
determine the velocity of sound.
ONE OF THE SMALLER INpUsTRIEs.-
The manufacture of thimbles has now
been so far perfected by means of i'm
proved machinery and processes, as to
involve a complete revolution ii this
comparatively small but useful industry.
In the first operation, 4 lot of bright sill
yer dollars, fresh from the mint, are put
into crucibles and melted into solid
ingots. They are then rolled into the
required thickness, and cut by Il stamp
into circular pieces of the desired size.
These circular disks are placed under
solid metal bar of the proportion of the
inside of the projected thimble, which,
moved by powerful machinery, descends
in a bottomless mold of the outside of
the thimbie, and presses the metal into
the needed shape at single blow. The
remaining operations Of Frightening.
polishing and decorating. are performed
by means Of lathe. First, the blank
form is fitted with rapidly-revolving
rod; slight touch of sharp chisel
takes a thin shaving from the end, an
other does the same on the SIDE, while
third rounds off the rim. The polishing
is done by round steel rod. which is
dipped in oil and pressed upon the sur
face. Small revolving steel wheels held
against the revolving blank pierce the
inden;ations on the lower half and the
end of the thimble: the ornamentation
is done by a similar process. All that
remains 10 be done TO the thimbles is to
brighten and polish the insides, boil
them in soapSudS to remove the oil,
brush them up and pack them for the
market-being sent to all parts of the
world.
AGRICULTURAL NOTES.