Cc. RELATION OF ELECTRICITY TO IRRIGATION WORKS. 
’ These figures support the opinion now generally held 
that water power when developed without excessive capital 
expenditure is the cheapest source of mechanical or elec- 
trical energy. When however the hydraulic engineering 
expenditure has been heavy, the margin between the 
relative costs of water and steam power is greatly narrov ed 
and sometimes disappears entirely. 
Hlectrical energy generated by falling water is costing 
more at Rheinfelden at Zurich and at Buffalo than it would 
cost in South Lancashire if generated by steam power in 
large units, and the margin between the actual charge for 
water power at Niagra and the estimated. cost of steam 
power in large generating stations in South Lancashire is 
only 12/- per H.H.P. per annum. 
Since these figures were collected, great improvements 
have been made in the operation of steam driven plants, 
larger units have been built and the steam turbine has come 
into greater prominence, bringing with it lower capital cost. 
Coal handling apparatus and automatic labour saving 
machinery has also been improved, and the cost of producing 
electricity from coal has been lowered in consequence. 
A still more recent development and one which bids fair 
to have great influence on future power schemes, is the 
Mond gas system, which provides probably the most perfect 
means of consuming fuel, and under proper conditions the 
most economical means of producing electricity from fuel. 
Gas engines of 1,000 H.P. are in daily and successful | 
operation, and larger sizes are now being built. These 
large engines are not operated with illuminating gas but 
with blast furnace and producer gas having a low calorific 
value. The generation of electricity by gas engines has — 
not been adopted to any great extent, although many 
attempts to do so have been made. Hitherto the saving 
has been inconsiderable and has not compensated for other 
