BY JAMES TOLSON, ESQ. 81 
former), to increase and multiply to an extent almost 
incredible, our efforts should be directed to lowering the 
temperature of the meat to 35° as speedily as possible. 
It may be taken for granted that whatever the result as 
to the toughness or condition, &c., of the meat may be, if 
such be caused by too rapid freezing, if the germs of 
in the following table, the units of heat dissipated and the rise in the 
temperature of the air contained in the room will be found in columns 
4and 5. 
Table showing the heat gained in one hour by 40,000 feet of air contained 
in an enclosed space, and passing through a circulating fan of different 
dimensions and running at the speeds given. In degrees Fah.; also 
the energy required to drive the fan in foot-pounds per minute, and 
in units per hour. 
Size of Exit open-] Actual Velocity of the Air, 5 feet J Actual Velocity of the Air, 10 feet 
& | ing in feet. per second. per second. 
oll | vo . |eaol = [ae te eer iron fee pees 
s G8 /a We! B y (Bs [Se fee! & u |ES 
3 Sa =m 5 |%y TES Sm Shey ee 
“oD = Gee oes ro) md oz je ot rs) 72 
ORO ct ts : ae (OB se] aa = ly meen | mec ag| = vs 
Fil is a) a oe jae S| oe pe lear) | Pere SSl aS = 
Be OS 30 oi So joo Has oOo |lsoul ok lo es] as Be ies Sin 
lee: (Oe leet ee eee lg Oba ae el ae og pe gee 
geen sires 2a a 88] 2 [-She2aloes| 86] 2 [Fas 
BS > o 3 & j9aul es laee) so a ([2a¥ 
3 8 2271 od [s42u} 8 Se cr | 
= ze = |” (eeele" (6sele | o bee 
Balas, | Sal) 257 96 | 7°50 146 | 1620] 384 | 30 | ‘o4 
4 | ato} 274 |) 4°8 171 | 13°25 108 2880 | 684; 53 yi 
eles | ScORI Ek 204 | 20°45 88 | 4500 | 1068 , 83 II 
6} 3°0 |] 36] 108 385 30 44 6480 | 1540 120 10 
Ba 335.) 472) 047, 524 40°95 14 8820 | 2096 | 163 22 
8} 4:0 | 4°8 | 19°2 685 | 53°25 56 |11§20 | 2740 | 213 3° 
9] 45 | 574 | 24°3 867 67°50 50 |14580 | 3468 270 37 
10 | 570 | 6°0 | 30°0 1070 83°25 44 |18000 | 4280 333 40 
12 }| Go |= 7°2' | 4372 1540 120 36 |25920 | 6160 480 66 
15} 7-5 | 9°70 | 67°5 2403 | 187 30 |40500 | g610 747 | 1°03 
. 3) 4) (x) | (@) 1 @) (4) (5) 
machine is finally resolved, cannot exceed the amount (expressed in power) 
required to drive it, we are at once enabled to calculate very exactly the 
actual heating of the air that will take place in any enclosed space under 
the conditions above described. As many trials have been made with 
blowers or fans for the purpose of producing rapid circulation, and the 
result being an immediate and very considerable rise in the temperature of 
the air, the gain of heat was attributed entirely to compression by the fan, 
and to the friction of the machine. If the heat evolved by the fan is 
limited absolutely by the amount of power required to drive it, and if the 
heating of the air is found to exceed the amount due to this cause, the 
excess must be due to one of two other causes :—Either it must come 
through the walls, or it must be removed from the meat hanging in the 
room. If the insulation is perfect the conclusion that the excess of heat is 
derived from the bodies hanging in the room is obvious, and as the quantity 
of heat contained in them is limited, the quicker it is removed the sooner 
will their temperature be reduced to the required point. 
G 
