Courier Democrat. (Langdon, N.D.) 1891-1920, 1893-06-01
"Hor.e, Power of Boilers.

ssHOrse Power" of Boilers.
If the boiler is new, or has never been
tested, the heating surface is the best
guide to a knowledge of what it will
be capable of doing. If, says the Lo-
connective, the boiler is well designed
or properly set, two pounds Of water
should be evaporated for each square
foot of heating surface, so that, on the
Centennial committees basis, fifteen
square feet of heating surface should
be allowed per horse power of a boiler,
the external surface of that portion of
the shell which is exposed to the fire
should be estimated, and to this, ex-
pressed in square feet, should be added
the area of the tubes, and Of such por-
tons of the heads as are exposed to the
direct LIT. The sum should then be
divided by fifteen, and the result is the
nominal horsepower Of the boiler. This
rule is not absolute, but like all other
rules it has exceptions. With the most
approved settings, and with well man.
aged fires, the evaporation is greater
than that estimated above, and we find
that in such cases twelve feet square Of
heating surface will evaporate the guam
power. In some exceptional cases the
requisite heating surface is even less
than twelve square feet, but we do not
use less than twelve unless we have sat
istied ourselves, by careful experiment
upon similar boilers, similarly set, that
we may do so fairly. On the other
hand. if the boiler or the setting is
poorly designed, or the draught more
imperfect, or the fires badly handled,
more than fifteen square feet may be
required. There is no such thing pos
sible as an absolute rule for the horse
power Of boiler, and the rule we have
above merely represents what, in our
experience, given boiler, well de-
signed, may be expected to 10 under
ordinary circumstances.
The Phenomenon of Projectiles.
One Of the most widely discussed sub.
jects at the present time among astron.
omers, says thu Boston Journal Of Com.
merce, is the phenomenon of projectiles
and to Flammarion is due one Of the
most original and valuable contribu
lions in this line, though differing in
his views to a considerable extent from
those entertained by some other author
tiles. Thus, in the relation Of projec
tiles hurled from the earth's surface, he
argues that body thrown toward the
sun will simply fall upon it, and body
| cast in the opposite direction from the
sun would penetrate far into the depths
of space, if by any exceedingly rare
chance, the same path was not being
| traversed by Jupiter. Saturn, Uranus
or Neptune, thus modifying it's course
| at it's return, however, it would be at
tracted by the entire solar system in
stead Of by the sun alone, and would
come back toward the point of the
| terrestrial orbit, whence it started, this
happening at each revolution, as long
| as the earth was not encountered tt
arrest and terminate it's career. Flam
marion is also of the opinion that, il
| the earth formerly had volcanoes
| capable Of throwing out such pro
| jectiles, they all, whatever their mum
| Der, return and cross the terrestrial orbi
| at every revolution, and they reach i
with the velocity Of comets and shoot
ing stars, that is, with the velocity
caused by solar attraction added tt
| their own velocity-in u word not sim
| ply with the circular velocity Of the
earth's annual revolution about the sun
| 29,5OO meters second, but with ar
| elliptical velocity having maximum
| limit of II, 700 meters.