The Austin weekly statesman. (Austin, Tex.) 1883-1898, 1884-01-24
MECHANICAL NOTES.

A London steam boiler company
lights up the interior of boilers in
such way that the little cascades,
currents. and whirlpools in the water
in the course of steam formation may
all be observed.
A soft patch is q temporary eXpe-
dent for stopping leak, but in many
boilers which have become wasted
away through long service, it is
about the only thing which can be
used, as there is no good metal to
rivet to anywhere near the leak, and
it would be impossible to make job
of riveting that would bear the strain
of caulking. The patch, if on the
outside of the boiler or removed from
the fire, may be applied as plaster
directly upon the iron without cut
ting away the defective part; but if
over or near the fire, the defective
part should be cut away, so that the
water may have access to the sheet
of the patch.
Ordinary hydraulic cement is said
to be greatly eXcelled in value, as a
mortar and in power of resistance to
the action Of water, by a French min
eral composition which has been
brought forward, and for which are
also claimed the advantages of being
unaffected by air or acids, and of ac-
quiring stony hardness of 230 de-
grees, retaining this even in boiling
water. This article is prepared by
subjecting mixture of nineteen
pounds of sulphur and forty-two
pounds OF pulverized stoneware and
glass to gentle heat, sufficient to
melt the sulphur, and stirring it until
a perfectly homogeneous mass is
formed, when it is run into vessels
and allowed to cool. The material
thus produced melts at about 248 de-
grees, and can, like asphaltum, be re-
peatedly used by heating it gently.
The weight of an AK, says an ex-
perienced Eau Clyire logger, is arbi-
traTy, and dependent upon the choice
of the aXeman for the purpose in
tended. If the object to be cut is
small timber, which may be severed
at from one to half dozen blows, an
axe with long, thin blade, and as
little bevel as is compatible with
strength, is chosen, and at every stroke
the blade is buried to the helve. An
other Chippewa lumberman says, if
the purpose he to fell large trees or
cut heavy timbers, and this same axe
is used, it bites deeply in its strokes,
but the chips remain in the timber af-
ter its missions, and many more blows
are required to dislodge it than were
necessary to its formation; therefore,
for this purpose, an axe having
thick, heavy bevel, and cutting much
less deeply, is selected. The bevel,
now acting as a wedge, forces out the
chip at the same stroke by which the
incjSiOn is made
VIM. Barr, who is somewhat of an
authority on the subject, says that the
great majority Of buyers of steam
boilers have but little knowledge on
the subject Of tests, and too often con-
clude that, If they have a certified copy
of Il record showing that particular
boiler withStood a test of say $50
pounds, it is a good safe boiler at 70
to 100 pounds steam pressure. If the
boiler is a new one and by reputable
maker that may be true; if it has been
in use and put upon the market as a
secondhand boiler it may be anything
but safe ut halt the pressure named,
By the hydraulic test the braces IN a
boiler may be broken, joints strained,
so as to make them leak, bolts or pins
may be sheared off OF so distorted as to
be of little or no service in resisting
pressure when steam is on. The prac-
tice of inspecting boilers by sounding
with hammer is in many respects to
be commended. 1t requires some |
practical experience in order to detect |
blisters and the wasting of plates by |
sound alone. The hammer is espe-
cially applicable to the thorough in
spection of old boilers.