rpetuate the advantage at present held by manufactories
situated on ports and harbours; and this, of course, will apply with
peculiar force to the cases of articles of considerable bulk. Where a
very great deal of power is needed for the making of an article or
material of comparatively small weight and bulk proportioned to its
value--such for instance as calcium carbide or aluminium--the
immediate vicinity of the source of natural power will offer
superlative inducements. But an immense number of things lie between
the domains of these two classes, and for the economical manufacture
of these it is imperative that both cheap power and low wharfage rates
should be obtainable.

An increasingly intense demand must thus spring up for systems of long
distance transmission, and very high voltage will be adopted as the
means of diminishing the loss of power due to leakage from the cables.
Similarly the "polyphase" system--which is eminently adapted to
installations of the nature indicated--must demand increasing
attention.

Taking a concrete example, mention may be made of the effects to be
expected from the proposed scheme for diverting some of the headwaters
of the Tay and its lakes from the eastern to the western shores of
Scotland and establishing at Loch Leven--the western inlet, not the
inland lake of that name--a seaport town devoted to manufacturing
purposes requiring very cheap supplies of power. It is obvious that
the owners of mills in and around Glasgow, and only forty or fifty
miles distant, will make the most strenuous exertions to enable them
to secure a similar advantage.

It is already claimed that with the use of currents of high voltage
for carrying the power, and "step-down transformers" converting these
into a suitable medium for the driving of machinery, a fairly
economical transmission can be ensured along a distance of 100 miles.
It therefore seems plain that the natural forces derived from such
sources as waterfalls can safely be reckoned upon as friends rather
than as foes of the vested interests of all the great cities of the
United Kingdom.

The possibilities of long distance transmission are greatly enhanced
by the very recent discovery that a cable carrying a current of high
voltage can be most effectually insulated by encasing it in the midst
of a tube filled with wet sawdust and kept at a low temperature,
preferably at the freezing point of water.

Wireless transmission of a small amount