1918.] 
The N.Z. Journal of Science and Technology. 
55 
freezing-works, and so utilizing it to the utmost. In a sense, electric power 
for such a purpose partakes of the character of a by-product, as the annual 
cost of power from a water-power source is practically the same whether 
used for three minutes in the year or for the whole year. 
Another example of an industry which may be said to be almost 
dependent upon a general power system for its existence is that of crushing 
limestone for agricultural purposes. If limestone is to be obtained in 
quantities and at such prices that the agriculturist can afford to use it in 
such large quantities as seem desirable, it can only be obtained as the 
result of the application of power to crushing in chosen localities, and to a 
large extent upon the farm itself, so as to save handling and bagging. In 
other words, electricity must be brought to the quarry and the farm ; and 
once it is brought to the farm it opens out vistas of development previously 
unthought-of, resulting in increased production and closer settlement, besides 
taking the place of oil-engines in shearing, milking, wood-chopping, and other 
mechanical uses, and the place of steam for threshing. We find that 
steady progress is being made with the use of electricity as a stimulant 
of certain crops, whilst on land suited for the purpose the electric plough 
seems to be making headway. Closely connected with the agricultural 
industry is that of light railways, by which is meant a class of railway 
suited for rural service as distinct from trunk railway-lines or even branch 
lines-—-a kind of railway, in fact, which serves the same purpose for a rural 
community as a tramway does for a town population, except that goods 
would predominate over passengers. Such light railways cannot be operated 
satisfactorily except by electricity, the cost of which is, however, prohibitive 
unless obtainable from a general electric-supply system. Examples may 
be multiplied, but enough has been said to show how a power system 
gives birth to new industries and activities which are wholly or partly 
dependent upon a supply of electric power being generally available 
throughout the country. 
Conclusions. 
It has been shown that the establishment of a general power-supply 
system leads to an economy in capital, fuel, and labour ; that it enables 
the power-user to develop his business and to increase his output unhampered 
by considerations relating to the inadequacy of his plant; that the power¬ 
lines provide a means of absorbing power from sources which are other¬ 
wise wasted or remain undeveloped ; and that the facilities offered make 
new industries possible, and promote closer settlement. The saving in 
fuel alone is sufficient to enable the capital expenditure in a power-supply 
undertaking to be recovered in about five years’ time, without taking 
credit for other economies effected. The result is a substantial increase 
in national efficiency. An increased efficiency, however, has a cumulative 
effect, because it invariably leads to increased production for the same effort. 
This in turn adds to the efficiency as a result of increase in the volume of 
business transacted, which again reflects upon production, and so on, until 
equilibrium is reached. 
Enough has been said to support the contention that a power-supply 
system with distribution within reach of all, capable of satisfying the needs 
of the agricultural and industrial community, is a necessity as a means of 
fully developing the resources of a State, and that the economic gain to the 
community is so great that no nation which means to survive can afford 
to neglect the means of securing it. 
