great advantages over coal-gas as to affect the choice of electric
lighting. But in the cases where there is no public gas-supply, and
current must be generated from coal or coke or oil consumed on the spot,
the cost of the skilled labour required to look after either a boiler,
steam-engine and dynamo, or a power gas-plant and gas-engine or oil-
engine and dynamo, will be so heavy that unless the capacity of the
installation is very great, acetylene will almost certainly prove a
cheaper and more convenient method of obtaining light. The attention
required by an acetylene installation, such as a country house of upwards
of thirty rooms would want, is limited to one or two hours' labour per
diem at any convenient time during daylight. Moreover, the attendant need
not be highly paid, as he will not have required an engineman's training,
as will the attendant on an electric lighting plant. The latter, too,
must be present throughout the hours when light is wanted unless a heavy
expenditure has been incurred on accumulators. Furthermore, the capital
outlay on generating plant will be very much less for acetylene than for
electric lighting. General considerations such as these lead to the
conclusion that in almost all country districts in this country a house
or institution could be lighted more cheaply by means of acetylene than
by electricity. In the tabular statement of comparative costs of
different modes of lighting, electric lighting has been included only on
the basis of a fixed cost per unit, as owing to the very varied cost of
generating current by small installations in different parts of the
country it would be futile to attempt to give the cost of electric
lighting on any other basis, such as the prime cost of coal or coke in a
particular district. Where current is supplied by a public electricity-
supply undertaking, the cost per unit is known, and the comparative costs
of electric light and acetylene can be arrived at with tolerable
precision. It has not been thought necessary to include in the tabular
statement electric arc-lamps, as they are only suitable for the lighting