450
MOLESWORTH ’s POCKET-BOOK;
STEAM.
Mercurial Gauge.
*1 atmosphere,or 14-706 lbs. ) „„ . , ,
per square inch .. .. f = 29'92 lnches of mercury.
Each lb. pressure per square
inch.. .. ..............j-----tJd&-
Each lb. pressure per square > ,
inch.. .. > = 1'018 rise in a siphon gauge.
. =1 Inch approximately.
Each atmosphere, or 14-706 ) „„ „ ... . „
lbs. per square Inch ., f — 33 9 eet water.
Each lb. per square inch .. =27’68 inches of water.
Velocity of Influx of Steam in Vacuo.
T — Temperature of steam.
V = Velocity of steam in feet per second.
V = 60 V T + 459.
Rule for the Elastic Force of Steam.
F = The force in inches of mercury.
T = The temperature (Fahr,.) of the steam.
p=
C = 177 for fresh water.
= 177’6 „ sea water *
= 185-6 „ „ „ saturated with salt.
Temperature and Volume of Satuhated Steam.
P — Pressure in lbs. per square inch, atmosphere included.
T == Temperature of steam in degrees Fahr.
V = SpeciDc volume of steam or cubic feet of steam from
1 cubic foot of water.
The columns three and four in the Tables in the following
pages are calculated from the following formulae:—
m 2938-16
T=6Ü9Ä^7B-37V85-
„ 20559 „
V = —— ; or log. V = 4-3135 - (-941 X log. P).
* In common practice an atmosphere is generally taken as
15 lbs. per square inch.
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