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result of all classes of generating plant. The load-factor is, of course, higher for water-power plants than for fuel plants, the figures for each type being as follows : —

In order to determine exactly the day load-curve — i.e., the distribution of the load over the various hours of the day—arrangements were made with the engineers of the fifteen largest powerstations, comprising 78 per cent, of the plant capacity of the Dominion, to take half-hourly observations of the loading on the 30th September, 1920, and the 30th June, 1921, as representing typical equinoctial and midwinter loading. These figures were very courteously supplied, and the total results have been plotted in the graph herewith. These curves show a very large difference between the summer and winter demand, although the normal growth in the demand over a period of nine months is also

Curves showing Half-hourly Observations of Loading.

Units Output. Maximum. Annual Load-factor. I Water-power Steam-engines Gas-engines Oil-engines 91,334,719 50,848,365 5,616,528 1,676,767 Kilowatts. 21.661 17,587 2,157 530 Per Cent. 47-8 32-9 29-3 36-2