There will result the curve r, r, r, which determines the power which at any point in the diagram is to be regarded as a loss, to be carried to the debit side of the account. This curve of losses intersects the curve of gains at a point (it is evident) where each equals the other.
Therefore this is the point at which expansion should cease, and this absolute pressure is the economic terminal pressure, which determines the number of expansions profitable under the given conditions.
In the foregoing example are taken k = 0.3070554, t' = 331.169, t = 60, while the back pressure was taken at 7 pounds.
By way of further illustration, first let the back pressure be changed from 7 to 5.
By equation 1 there will result a new curve of gains, W, W, W, a portion only being plotted.
Second, let t' = 331.169 as before.
t = 150 instead of 60.
k = 0.2507097 instead of 0.3070554.
There will result the second curve of losses, R, R, R, intersecting the second curve of gains at the point F, the new economic point for our new conditions.
These two examples fully illustrate the whole subject, furnishing an easy and, when carefully made, a very exact calculation and result.
The following are a few of the general conclusions to be drawn:
1. That radiation is a tangible and measurable cause, sufficient to account for all losses heretofore ascribed to an intangible, immeasurable, and wholly imaginary cause, viz., "internal evaporation and re-evaporation."