There is no doubt that London has been very largely responsible for the enormous development of motor transport within the British Isles. It is generally considered that Paris represents the nearest approach to London for purposes of comparison. Nevertheless, the population of Paris is only about half that of London, and the area within which that population is included is only about one quarter. In other words, the density of population of Paris is double that of London, which means that the average distance to be traversed in delivering goods to a given number of people is much smaller in Paris than it is here. Now the motor vehicle is able to show superior economy over horse-drawn traffic mainly where it is able to make use of its capacity for speed and its ability to cover, without tiring, long distances in the course of a day. For house-to-house deliveries the motor is at a disadvantage, since while it is standing waiting before a door it represents a larger idle capital than the horsed cart, and the investment of this larger capital can only be justified if it results in the vehicle performing in a given time a far larger amount of work than would be possible if horses were used. Taking, for example, the case of a 2-ton motor van capable of running about 100 miles in the course of a working day, the ideal condition is represented by a run under full load from the warehouse or store to some point about 50 miles distant. Here the whole load is delivered, and a complete return load is found. Such conditions are seldom available in practice, but the nearer it is possible to approach to them, the more likely is the motor to prove a profitable investment. On the other hand, supposing the car to be used for house-to-house work involving, let us say, 100 deliveries in the course of a day with a total distance covered of only about 10 miles, the motor may cover this distance in traffic in something like an hour, whereas a horsed vehicle might take two hours. The saving in that case is comparatively small, and represents, let us say, only an additional 10 deliveries or an advantage of 10 per cent. extra in the work done in the day. On the other hand, the cost of the motor is very much higher, and it is more than likely that on economical grounds the operating concern would not be justified in adopting mechanical transport.