ARTIFICIAL REFRIGERATION AND ICE MAKING. LXXIII, 
Mr. Houghton’s experience with the repeated fracture of the 
piston rod of a cold air expansion cylinder is not unique, 
because the Glebe Island machine had similar trouble. But the 
cold air machine designed by the author and shewn by illustration 
has worked for over twelve years now without once having a 
similar mishap, 
Mr. Stokes corroborated the necessity which exists in ordinary 
cases for setting the engine crank at right angles to that of the 
compressor, and drew some diagrams which were practically 
identical with those shewn by the author to illustrate the amount 
of power required to be stored in the fly wheel of a compressor 
under ordinary conditions. He, Mr. Stokes, summed up the 
qualities of his ideal compressor thus:—Few parts of ample size 
with two vertical single acting compressors and the engine between 
them, vertical for small sizes and horizontal for large machines. 
He must have lost sight however of the fact that in comparing 
such an arrangement with that of the Antarctic machine he had 
to provide three sets of guides, connecting rods and cranks, and 
three separate lines of force instead of one; that the sum of all 
the strains instead of the differences has to be borne by the bear- 
ings, that expensive crank forgings were necessary to make a good 
job, and that the power lost by friction would probably be about 
three times as much as in the direct acting machine. 
In the past large profits were attached to the working of 
refrigerating machinery and economy of power was not a matter 
of great importance, but with the competition and continual 
Striving for improvement daily taking place, any arrangement 
which reduced the frictional losses as well as the wear and tear 
by more than one half was a much more serious matter, and led 
the author to work out the arrangements shewn in Figs. 8 and 9. 
