MR. MACQUORN RANKINE ON THERMO-DYNAMICS. 
153 
and the heat stored up, per pound of air per stroke, is 
K V (T,— T 2 )+«.hyp. log 
T i+ T o 
^ 1 + PoV„) 
< 
t 2 +t 0 
V 1 + P 0 V 0 ) 
. . (49 a.) 
(33 a.) Numerical Examples. 
To illustrate the use of these formulae, let us take the following example : — 
Temperature of receiving heat, T, = 343°‘3 Centigrade. 
T!-|-T 0 =615 o '8 Centigrade. 
Temperature of emitting heat, T 2 = 35°'4 Centigrade. 
T 2 +T 0 =307 o, 9 Centigrade. 
Vp 
Ratio of Effective Expansion, 
From these data are computed the following results: — 
Maximum Efficiency, — 
307°-9 I 
615°’8 2 f 
Heat expended, or latent heat of expansion, — 
6 1 5 B 3 
H, = P 0 V 0 X 5^5 X hyp. log 9 = 24020 foot-pounds per pound of workingair per stroke. 
Heat abstracted by refrigeration, — 
307’9 3 
Ik=P 0 V 0 x^~ Xhyp. log 2 = 12010 foot-pounds per pound of workingair per stroke. 
Work performed, — 
307-9 3 
H, — H,= P 0 V 0 X 279^5 X hyp. log 5 = 12010 foot-pounds per pound of working air per 
stroke. 
To exemplify the computation of the heat stored by a perfect regenerator, let it be 
supposed, in the first place, that the indicator-diagram resembles ARC'D' in fig. 19, 
where the curves of equal transmission are represented by a pair of lines of constant 
pressure. Then the heat to be stored is 
K P (Tj— T 2 )= 101,800 foot-pounds per pound of workingair per stroke. 
Secondly, let the diagram resemble ABCD in fig. 19, where the curves of equal 
transmission are represented by a pair of lines of constant volume. Then the heat 
to be stored is 
K V (T,— T 2 ) = 72,233 foot-pounds per pound of working air per stroke. 
Thirdly, let the curves of equal transmission, as in a recent example, be hyperbolas, 
concave towards OY, and let the arbitrary constant a have the following value, — 
«=P 0 V 0 =26214'4 foot-pounds; 
MDCCCLIV. 
X 
