re is strong evidence that where steam is the
power agent to be employed the water-tube type of boiler is likely to be
employed, and to the exclusion of all other forms of apparatus for
the generation of steam. The advantages of this type, particularly the
tubulous form (or a small water tube), made as it is in sections, offers
unrivalled facilities for transport service. The heaviest parts need
not exceed 3 cwt. in weight, and require neither heavy nor yet expensive
brickwork foundations.

WATERLESS POWER.

The difficulties in finding water to drive a steam plant are often of
such a serious character as to involve the abandonment of many payable
mines; therefore, a motive power that does not require the aqueous agent
will be a welcome boon.

It will be a source of gratification to many a gold-claim holder to know
that practical science has enabled motive power to be produced without
the necessity of water, except a certain very small quantity, which once
supplied will not require to be renewed, unless to compensate for the
loss due to atmospheric evaporation.

Any carbonaceous fuel, such as, say, lignite, coal, or charcoal, can be
employed. The latter can be easily produced by the method described
in the Chapter on "Rules of Thumb," or by building a kiln by piling
together a number of trunks of trees, or fairly large-sized branches,
cut so that they can be built up in a compact form. The pile, after
being covered with earth, is then lighted from the base, and if there
are no inlets for the air except the limited proportion required for the
smouldering fire at the base, the whole of the timber will be gradually
carbonised to charcoal of good quality, which is available for the
waterless power plant.

The waterless power plant consists of two divisions: First, a gas
generating plant; secondly, an internal combustion or gas engine in
which the gas is burnt, producing by thermo-dynamic action the motive
power required. The system known as the Thwaite Power Gas System is not
only practically independent of the use of water, but its efficiency in
converting fuel heat into work is so high that no existing steam plant
will be able to compete with it.

The weight of raw timber, afterwards to be converted into charcoal, that
will be required to produce an effective horse-power for one hour equals
7 lb.

If coal is the fuel 1 1/3 lb. per E.H.P. for one hour's run.

If lignite is the fuel 2 1/2 lb. per E.H.P. for one h