Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1880-07-10
MECHANICAL NOTES.

INDIA RUBBER HOSE FOR HIGH STEAM
PREssURE. At late meeting of the
Edinburgh Association of Science and
Arts, held recently, short communication
was made by William Firth ON the use of
india rubber hose for steam and high pres
sure purposes. He exhibited piece of
canvas and rubber hose capable Of with
standing pressure of 1000 pounds to the
square inch, and also several other pieces
of canvas and rubber packing which, he
said, were most useful for engineers.
PERFECTION OF MODERN MACHINERY.
The degree of perfection that machinery
has reached is shown by the work of the
new Indiana State-house. But seven men
are building this immense structure, and
their progress daily is from seventeen to
twenty times greater than that of the large
force of workmen employed when the
Court house was built. The cause of this
great saving is the little g traveller now
in use at the State.house. These are small
engines that run upon the scaffold tracks
in all directions, and do work which re-
auired fifteen men with the old hand der.
ricks. They also save much time, for a
stone that was formerly laid in from two
to seven hours, is now placed in position in
fifteen minutes, with scarcely any trouble
or extra exertion ON the part of the work
men.
TUBE WELLS FOR LARGE Supplies OF
WATER.-For the last eight or nine years,
the leading breweries at Burton on Trent
have obtained the bulk of their water sup
plies from number OF tube-wells con.
nected with one pump. Allsopp & Co.
pump 600, 600 gallons daily from 30 3-inch
wells, and Bass & Co. 800, 900 gallons from
25 tubes Thus, in one town, two brew
cries are obtaining sufficient water for
town of 10000 inhabitants. Although
some Of these Burton wells are within a
stones throw from the Trent, the quality,
level and temperature Of the water differ
from those of the river water. The town
of Carmarthen, in Wales, is supplied by 10
Pinch tube-weIls. In sandy soils, strain
ers or filters are used, which prevent sand
coming into the tubes. a tube-well was
sunk in a very fine sand at Chisei-
hurst, by pumping up six barrow
loads of sand and replacing it with gravel.
One advantage of the gravel filter is its
imperishability, and if made sufficiently
large, the velocity of the water is not suf-
ficient to bring the grains of sand within
the area. acted upon by the pump. In
rocks and other hard strata the method of
sinking tube-w wells is similar to that en-
ployed in making artesian borings; but the
mode of pumping and development of sup
ply are entirely different from the tube
well system. Bored tubewells can be
made through any stratum and to any
depth that an ordinary artesian boring can
reach. The Lower Grounds, Birmingham,
with their ornamental waters, fountains,
and extensive gardens, derive their entire
water-supply from a single 5.inch well
sunk about two hundred feet deep. BY
means Of this well an annual saving of
f300 for water.rate is effected. Two tube
wells at West Thurrock yield a daily sup
ply of 220. GOO gallons from the chalk.
SELECTING Tool. STEEL. ten
acity, facility of working under the ham,
mer, and of receiving temper, are requi-
sites of good tool steel. The presence or
absence Of some of these qualities cannot
be ascertained except by actual expert
ment yet good judgment will enable
man to ascertain, with an approach to
accuracy, the quality of steel without SUBJ
iecting it to the action of fire and water
and the hammer. Pure iron contains no
carbon, but tool steel contains from to 2
per cent. So small is this amount, that it
is not surprising that it requires judgment
and experience to select steel III the bar.
One of the tests is to apply drop of
nitric acid to the surface of fresh frac-
ture. 1t will leave black stain on good
steel, but not on iron or low steel. An
other test is to observe the color and tex
ture of freshly made fracture. This should
present fine grain, with duh silvery
luster, and of uniform color. Poor steel
may show close grain, but it will be
notified in color. But the only sure test
is in working the steel. Draw the end of
tie bar, heated to a cherry red. under the
hammer, to fine point If it will admit
of being so pointed, that is good indica-
ton. Plunge it into the hardening bath
while hot, and when chilled, give it few
gentle blows with the hammer. If it is
tough and does not fly, but requires some
hammering and bending back and forth to
break it, that is another good indication.
If the fracture shows fine, even, lively
grain, the test is complete aud the work.
man may be satisfied. One Of the best
tests is to make and temper cold chisel
from the bar. If it stands well the chip
ping on casting the steel will make good
turning tools. But, after all, the good
Judgment of the experienced forger is worth
moro than emnirical tests