22 
The N.Z. Journal of Science and Technology. 
[Jan. 
* practice that the average power actually used in small factories is usually 
from one-half to one-quarter of what the owner estimates—his estimates 
being based on maximum rather than on average power. The average 
small steam plant on a 15- to 20-per-cent, load-factor actually uses 6 to 
8 tons of coal per horse-power per annum. And thus the Lake Coleridge 
plant, replacing such plants and working up to a 50- or 60-per-cent, load- 
factor, saves 15 to 25 tons of coal per annum per horse-power of its useful 
output. 
Good suction-gas plants are more efficient when working at or near 
full load, but at ordinary load-factors those that have been replaced by 
Lake Coleridge power have not appreciably reduced the quantity of fuel 
saved pe ■ horse-power yea of electric output. 
It is well within the mark to put down the actual saving that has been 
effected by Lake Coleridge power, working a 50- to 60-per-cent, factor, at 
over 10 tons per horse-power year. 
The actual output of the plant at present from the Addington dis¬ 
tributing-station is 4,000 kilowatts— i.e., 5,300 horse-power, or, allowing 
liberally for losses in distribution, 4,400 horse-power delivered to the con¬ 
sumers. It is thus effecting an actual saving in fuel-consumption of over 
44,000 tons per annum, probably well over 50,000 tons, worth £75,000 
delivered into the coal-bins or £100,000 delivered into the boiler-fires. 
The greater portion of this saving is represented by the wages of miners,, 
railway men, seamen, wharf labourers, carters, firemen, and clerical hands, 
and represents the labour of nearly four hundred men, who are replaced 
by sixty to eighty men engaged on operating and maintaining the Lake 
Coleridge power plant, distribution, substations, and reticulation. 
To some considerable extent the electric power has replaced kerosene 
and petrol instead of coal; but to this extent the saving is of even greater 
national importance, in that it has substantially reduced ocean and rail¬ 
way transport, and has reduced our national liability to foreign creditors 
by probably £10,000 per year. 
Moreover, hydro-electric power is a step in the right direction in 
another important aspect. The hard, exhausting, unskilled, and mono¬ 
tonous labour of mining, trucking, shipping, shovelling, carting, and firing 
is replaced by the comparatively easy, clean, and scientific (though probably 
somewhat monotonous) employment of watching the turbines and attend¬ 
ing the switchboards, or the more interesting outdoor life of patrolling 
and maintaining the transmission-lines and distribution-lines. Instead of 
working underground, we now work away up amongst the mountains. 
Instead of demanding mere physical strength, the new method of power- 
supply calls for the highest development of ingenuity, initiative, and 
skill, even amongst its routine workers. 
The coal will not, of course, be left in the ground. The stimulus of 
industry will open up other uses for it. When burned in boiler-furnaces 
the whole of its valuable nitrogenous and coal-tar products are wasted, 
and of its heat-value at most 5 to 10 per cent, can be converted into power 
even with the most efficient plant. With new processes, an increasing 
quantity will first be distilled in gas-retorts for the recovery of the nitrogen 
and tar-products, and the coke will be employed in electro-chemical and 
electro-thermal processes, in which efficiencies of 50 to 60 per cent, instead 
of 5 to 10 per cent, will be obtained. In such directions as these, 
economies of the utmost national importance are already being effected,, 
and will become of increasing importance in the very near future. 
