John Farey, Esq.
10 August, 1831.
the original plan of carrying the passengers in the same four-wheeled Carriage with the engine.
As far as your experience has gone, which plan of Steam Carriage do you think will hereafter be most generally resorted to, that of an Engine Carriage, drawing after it another Carriage containing the passengers, or of conveying the passengers in the Carriage in which the machinery is placed?—I have not had experience in drawing by two Carriages, except by the analogy of what is done on railways, and hence I feel some difficulty in speaking positively upon that point; there are advantages and disadvantages to be considered in both modes, but all the mechanical considerations incline to one side, viz. to place the engines in the same Carriage with the passengers; that plan will certainly be lighter than when two separate Carriages are used, and also the weight will be laid on those wheels which are turned by the engines, as it should be, to give them a firmer adherence to the road; also one Carriage will steer and turn much better than two, and will go safer down hill, and will be cheaper to build and to work.
By that means great weight is saved?—Yes; perhaps one-third is saved in exerting an equal power. In stating my opinion of the probability of a profitable result, after twelve months' trial of three coaches to run regularly two hundred miles every day, with despatches only, I contemplated that the engines and passengers would be ultimately in one Carriage, because that plan has a most decided mechanical advantage in making progress along the road, and also in facility of steerage, and safety in going down hill, and fewer servants are required to manage one Carriage than two. On the other hand, all the constructions that have yet been tried with one Carriage, subject the passengers to more or less occasional annoyance from heat and noise, smoke and dust, and there is still an apprehension of danger from the boiler, hence passengers will invariably prefer to go in a separate Carriage to be drawn by the Engine carriage; that mode also offers a facility of changing the engine for another, or for post horses, in case it gets deranged,
