Page 515

The Wisconsin Lumberman.
to the deviation from the circular
form.
In a cylinder, made with flat ends,
the strength imparted by these ren-
ders it less liable to stretch at the
the extremities than at mid-length.
Such a cylinder has thus a tendency,
under internal pressure, to assume
the form of a barrel.
Assuming the material to be suffi-
ciently pliable, like india-rubber, and
able to bear sufficient stretching, the
sides would be further curved, and
the spherical form be eventually at-
tained by sufficiently increasing the
pressure.
In very short cylinders, the ends
play an important part in increasing
the resistance to bursting longitudi-
nally; and where the length does not
exceed the diameter, the strength
approaches that of a sphere. In
practice, however local weakness aris-
ing from various causes-such as cor-
rosion of plates and rivet heads,
flaws, &c.,-may lead to failure,
against which the aid from the ends
cannot be counted upon.
Again, in oval shaped boilers, the
end plates assist materially in main-
taining the shape against the ten-
dency to become circular under in-
ternal pressure. Since the aid lent
by the ends diminishes as the distance
from these increases, an oval boiler
is most liable to change of form at
mid length.
In consequence of their tendency
to alteration of shape under pres-
sure, it is almost impossible to give
any rules for the strength of ellipti-
cal boilers, as their resistance varies
with every change of shape, accord-
ing to very complicated laws.-Bos-
ton Lumber Trade
Now is the time to advertise in the
WIscoNmn  LumBEwBx.     The best
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Terms moderate. Subscription price
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CONSOLIDATION OF THE TRUCKEE (CALIFORNIA)
LUMBER COMPANIES.
The Truckee Republican of July
18th says:   "The Sierra Nevada
Lumber Association has recently
filed articles of incorporation in the
office of the Secretary of State, at
Sacramento. Al of the owners of
lumber mills on the Truckee river
and its branches (except one) are re-
presented in this association. We
understand it is not the design of
this combination of the lumber inter-
ests of this section to raise the price
of lumber. One of the principal ob-
jects is to have a uniform price.
Heretofore each mill has had to send
out its separate agent to Salt Lake
and other remote places, at heavy ex-
pense, to make lumber contracts.
In this one item each, mill would
spend perhaps $1,000 or $1,500 per
annum for traveling expenses,amount--
ing in the aggregate to from $10,000
to $15,000. A considerable portion
of this extra expense can be saved by
the consolidation which has been ef-
fected, without increasing the price
of lumber. It will benefit contract-
ors and lumber dealers from abroad.
They will not be compelled to travel
around to each and every mill to see
where the dry lumber is that they
want. Now they will only. have to
apply to the officers of the association
to obtain at once the information
they desire. A detailed statement
will be kept by the association of
the amount and kind of lumber on
hand at each mill and the length of
time it has been sawed. There is no
doubt but that if the association per-
fects its organization and carries out
its plans as they have been foreshad-
owed, the results that follow will be
beneficial not only to the mill owners,
but to this entire community.
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