The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1873-08-30
SCIENTIFIC AND MECHANICAL.

The WORK OF CIRCULAR SAw.-Nine-
ty thousand feet of lumber was recently
sawn at the mill Of John McEwan, Bay
City, Mich, in 344 hours, besides slabbing
for gang, with two sets Of cutting teeth,
SO in each set, without sharpening in any
way, each tooth cutting more than 200
feet Of lumber The saw never made an
imperfect run, and the lumber was sawn
much smoother than by any other method
The saw in question is five and half feet
in diameter and No. gage. This, in all
probability, is the greatest feat ever per
formed with a saw with the same number
OF cutting points without sharpening in any
way, 50 says the Lunlber8sdn's GGsette
This saw is provided with j. <. Emerson .
improved bits or teeth. Their points are
alleged to be tempered so hard that they
will cut glass and they weigh less than one
sixth Of an ounce. The saw is a novelty
in its way, very simple in construction, the
bits to be changed in five or eight minutes
and never working loose. The saw cuts
six inches to each revolution, dropping
from six to eight boards per minute. Man
ufactured Ly Emerson, Ford & Co., Of
Beaver Falls. Pa.
Mr.. EMMET DEwsAoRE, Of England, has
invented writing machine 1t is about
the size Of small sewing machine, has q
key board with three rows Of keys, each
marked with a letter or number, which
connect ingeniously with duplicate letters
and figures in metal. These impress them
selves, when properly manipulated on q
wooden cylinder, around which is rolled
the paper to be written upon. By its use
it is claimed that an expert can print o SEN
tence or an article from 80 to 100 per cent.
faster than it can be possibly written with
pen.
1T is stated, on the authority Of Les Mon
deS, that the addition of chalk to fuel causes
notable economy in fuel where the mix
ture is burned. The fire is first lighted
with wood and charcoal then a layer Of
chalk is added, and then layer of fuel,
and so on. A fire thus made up is said to
last long time and to give out a good
heat.
WATERPRooF PAINT FOR CANvAs.-The
following is a cheap and simple process for
coating canvas for wagon tops, tents, avn
ings, etc. 1t renders IL impermeable to
moisture, without making it stiff and liable
to break Soft soap is to be dissolved in
hot water, and a solution of sulphate oflron
added The sulphuric acid combines with
the potash Of the soap, and the oxide Of
iron is precipitated with the fatty acid as
insoluble iron soap. This is washed and
dried, and mixed with lnseed oil. The
addition Of dissolved india rubber to the
oil improves the paint.
NEW ROUTE FROM New YORK TO LON
DoN.-A quicker route from New York to
London is suggested, to wit: By rail to
Shippegan, ON the Gulf of St. Lawrence,
thence across the Gulf by steamer to st.
Georges Harbor, Newfoundland, thence
by raj to st. Johns, thence by steamer to
Valencia, Ireland, thence by rail to st.
Georges Channel and by steamer to Eng
land The time Of this route can be re-
duced to seven days and three hours, the
longest water steaming being 4 days, to
wit st. Johns to Valencia, l 600 miles
At the present time from 10 to " days is
occupied by the fastest steamers in sailing
from New York to Liverpool.
MINING PIcKs.-A number Of patents
have been secured to present the miner
with pick with shifting points, says the
Mining Journal, all of more or less merit,
but none have come into amy extended use +;
but if such tool could be manufactured
70 meet the requirements Of the miner for
working hard ground, no dOubtit would be
saving of time, material, and muscle, as
the miner could take equivalent to a dozen
picks in his pocket, each point not weigh
ing over six ounces, which, being made Of
the best cast steel, would do good service.
To RESTORE CoLoR-When color on q
fabric has been accidently or otherwise de-
stroyed by acid, ammonia is applied to
neutralise the same, after which an sppli-
cation Of chloroform will, in almost all
cases, restore the original color. The ap-
plication of ammonia is common, but that
Of clorOform is but little known.
TEE yellow pine, an invaluable building
material for bridge and car work, is being
rapidly thinned out in the South. No tree
of this kind grows afterward where one is
cut, but only a worthless scrub pine Of an
other species. Those who now set out new
plantations of these trees will, in few
years, find them very valuable.