San Andreas independent., 1857-04-04

Deductions from preceding Experimental. That
the quantities of water discharged in equal
times by the same orifce, from the same head
of water, are nearly the areas of the orifices.
2 That the quantities of water discharged in
equal times by the same orifces, under differ
ent heads, are nearly as the square roots of the
corresponding heights of the water in the reser-
voir above the surface of the orifces.
3. That the quantities of water discharged
during the same time by different heights of
water in the reservoir, are to one another in the
compound ratio of the areas of the apertures
and of the square roots of the heights in the
reservoir.
4. That, on account of the friction, small ori-
ices discharge proportionay less fluid than
those which are larger and of similar figure
under the same altitude of fluid in the reser-
yoir.
5. That, in consequence of a Slight augmen-
tatlon which the contraction of the fluid vein
undergoes, in proportion as the height of the
fluid in the reservoir increases, the expenditure
ought to be a little diminished
3. That circular apertures are most advanta-
geous, as they have less rubbing surface under
the same area
Z. That the discharge of fluid through a
cylindrical horizontal tube the diameter and
length of which are equal to one another, is the
same as through simple orifice
8. That if the cylindrical horizontal tube be
OF greater length than the extent of the diameter,
the discharge of water is much increased, and
may be increased with advantage to four times
the diameter of the ori6ce
Mr. Peacocke observes 60 These formula
appear for the most part to be founded chiefly
on some hypothesis with respect to the mode in
which the water is acted on in passing through
the nine AttamDt- do b1-,
stract reasoning to apprehend and explain the
precise motion of the water, as also to estimate
the separate nature and amount of each of the
forces concerned in producing or retarding it's
tiow Thus gravity, friction, viscidty, &C., are
each attempted to be estimated in actual value.
either by means OF abstract reasoning or by
means OF what are supposed to be analogous
experiments, or both. Now this would be a
very good thing, provided it were possible to
do 1t; but 1t seems to me impossible. Iconfcss
cannot comprehend how these forces could be
practically analyzed so as to determine with
certainty the precise value of each. We have
seen how each inventor. of formula differs
from all the others in practical results, in des-
plte OF much acute reasoning and many elabo-
rate and careful experiments and calculations
The formule all produce materially different
results the one from the other and we shall
ALL these results differ materially from facts
In the exercise of my humble judgment, have
pursued course quite different from that of my
predecessors. have addressed myself directly
to the facts ascertained by actual experiments,
combinng-as those facts of course do-ALL
the forces actually and simultaneously con-
cerned in producing or retarding the flow of
water. have attempted no analysis, but have
endeayored, not without success, to adapt form
ul5e which shall accord with and obey the ae-
gregate laws respectively developed by each set
of experiments"
Table Of Comparison Of the Theoretic nth the Real
Discharges per Minute through an Orifce One
Inch an Diameter; also, through Tube of a
Cylir'dracal Form, One Inch IN Diameter and
Ttoo Inches long.
Constant alti Theoretical d. Real dscharg Real dscbar
tude OF the wa scharges tro in the the
ter In the re- circular orr time and thro time by cyl
serVolr, ABOVE nee inch In the same ORR indrica tube
he Ofd