The next point of difference is in the amount of the loads: the estimate is founded upon the assumption, that every engine shall start with its full complement of load, and that with this it shall go the whole distance. "The facts, however, are," says Mr. _Booth_, "that, instead of a _full load_ of profitable carriage _from_ Manchester, about half the wagons _come back empty_, and, instead of the tonnage being conveyed the whole way, many thousand tons are conveyed only half the way; also, instead of the daily work being uniform, it is extremely fluctuating." It is further remarked, that in order to accomplish the transport of goods from the branches and from intermediate places, engines are despatched several times a day, from both ends of the line, _to clear the road_; the object of this arrangement being rather to lay the foundation of a beneficial intercourse in future, than with a view to any immediate profit. Mr. _Booth_ makes a rough estimate of the disadvantages arising from these circumstances by stating them at 33 per cent. in addition to the original estimate.
The next point of difference is the fuel. In the original estimate _coal_ is assumed as the fuel, and it is taken at the price of five shillings and tenpence per ton: now the act of parliament forbids the use of coal which would produce smoke; the company have, therefore, been obliged to use _coke_, at seventeen shillings and sixpence a ton. Taking coke, then, to be equivalent to coal, ton for ton, this would add .162 to the original estimate.
These several discrepancies being allowed for, and a proportional amount being added to the original estimate, the amount would be raised to .601 of a penny per ton per mile, which is within one fortieth of a penny of the actual cost. This difference is considered to be sufficiently accounted for by the wear and tear produced by the very rapid motion, more especially when it is considered that many of the engines were constructed before the engineer was aware of the great speed that would be required.
"What then," says Mr. _Booth_, in the Report already alluded to, "is the result of these opposite and mutually counteracting circumstances? and what is the present position of the company in respect of their moving power? Simply, that they are still in a course of experiment, to ascertain practically the best construction, and the most durable materials, for engines required to transport greater weights, and at greater velocities, than had, till very recently, been considered possible; and which, a few years ago, it had not entered into the imagination of the most daring and sanguine inventor to conceive: and, farther, that these experiments have necessarily been made, not with the calm deliberation and quiet pace which a salutary caution recommends,--making good each step in the progress of discovery before advancing another stage,--but amidst the bustle and responsibilities of a large and increasing traffic; the directors being altogether ignorant of the time each engine would last before it would be laid up as inefficient, but compelled to have engines, whether good or bad; being aware of various defects and imperfections, which it was impossible at the time to remedy, yet obliged to keep the machines in motion, under all the disadvantages of heavy repairs, constantly going on during the night, in order that the requisite number of engines might be ready for the morning's work. Neither is this great experiment yet complete; it is still going forward. But the most prominent difficulties have been in a great measure surmounted, and your committee conceive, that they are warranted in expecting, that the expenditure in this department will, ere long, be materially reduced, more especially when they consider the relative performances of the engines at the _present time_ compared with what it was two years ago."