cannot exceed 2.5 amperes, representing a loss of three-fourths of a
horse power, or under 5 per cent, when four cars are running. But
apart from these figures, we have materials for an actual comparison
of the cost of working the line by electricity and steam. The steam
tramway engines, temporarily employed at Portrush, are made by Messrs.
Wilkinson, of Wigan, and are generally considered as satisfactory as
any of the various tramway engines. They have a pair of vertical
cylinders, 8 inches diameter and one foot stroke, and work at a boiler
pressure of 120 lb., the total weight of the engine being 7 tons. The
electrical car with which the comparison is made has a dynamo weighing
13 cwt., and the tare of the car is 52 cwt. The steam-engines are
capable of drawing a total load of about 12 tons up the hill,
excluding the weight of the engine; the dynamo over six tons,
including its own weight; hence, weight for weight, the dynamo will
draw five times as much as the steam-engine. Finally, compare the
following estimates of cost. From actual experience, the steam-engine,
taking an average over a week, costs--

£ s. d.
Driver's wages. 1 10 0
Cleaner's " 0 12 0
Coke, 58½ cwt. at 25s. per ton. 3 13 1½
Oil, 1 gallon at 3s. 1d. 0 3 1
Tallow, 4 lb. at 6d. 0 2 0
Waste, 8 lb. at 2d. 0 1 4
Depreciation, 15 per cent. on £750. 2 3 3
----------
Total. £8 4 9½

The distance run was 312 miles. Also, from actual experience, the