The relation then between the work expended and the actual cooling work performed denotes the efficiency of the process, and this is expressed by **Qt**/(Q2-Q1); but as in a perfect refrigerating machine it is understood that the whole of the heat Q i is taken in at the absolute temperature T 11 and the whole of the heat Q2, is rejected at the absolute temperature T2, the heat quantities are proportional to the temperatures, and the expression T,/(T 2 -T,) gives the ideal coefficient of performance for any stated temperature range, whatever working substance is used.

This 'meet me on the **QT** out in the woods' bothers me.

The same method applies for tangential areas, by taking A -2 PTp -}- **QT** 4 + RT r + ..

Sochnee, Catalogue des actes d'Henri I **QT** (1907); de Caiz de Saint Aymour, Anne de Russie, reine de France (1896); E.

Then since XS and **QT** are parallel and FIG.