Art. 1.-Experiments on the Performances of Horses on Railroads.

The following Tables will shew, on different railroads, where horses have been used for some years, the respective resistances; which the inclination of the road, and the friction of the carriages, presented to the action of the horse.

TABLE I.

Table of the line of road, on which one horse travels with six loaded carriages, each weighing 8540 lbs., similar to No. 1, Experiment I. Chapter VII. § 2; and returns with six empty carriages, each weighing 2604 lbs., same as No. 7, Experiment I. Chapter VII. § 2. Edge-rail, Killingworth Colliery Railroad; friction, loaded carriages 40 lbs., empty carriages 14lbs.

On examining the above Table, it will be seen, that the average resistance with the load is about 60 lbs.; and in returning with the empty carriages, 157 lbs. ; the mean, 109 lbs.-The distance, 2156 yards.

The horses were very large and heavy; they generally traversed that distance eight times a day, being in all about nineteen miles. There were four horses regularly employed, but it was found necessary to keep a spare horse, to give the others alternately a day's rest; so that, in fact, five horses were kept to perform the constant work of four horses effectively.

TABLE II.

Table of the performance of horses, upon the Backworth Colliery Edge-railroad, where a horse takes six loaded carriages, each weighing 9010 lbs. down the plane; and returns with six empty carriages, up the plane, each weighing 3080 lbs.

Friction of each loaded carriage 42 lbs., and of each empty carriage 15 lbs.

The preceding Table will shew the performance of the horses, upon a portion of the Backworth Colliery railroad; these horses, like those employed on the Killingworth railroad, were extremely powerful, as may be presumed. The average resistance with the loaded carriages is 42 lbs., and with the empty carriages, 189 lbs., giving a mean of 115 lbs. ; they traversed the distance backwards and forwards most frequently eight times a day, making nineteen miles. This Table may be taken as the maximum performance of horses, and will shew the resistance which a very powerful horse is capable of overcoming occasionally.

TABLE III.

Table of the performance of horses upon the Team Colliery edge railroad, where a horse travels with four loaded carriages down the plane in summer, and returns with the same number empty; and with three carriages in both directions in winter. Weight of loaded carriages 8540 lbs., friction 40 lbs., empty carriages 2604 lbs., friction 14 lbs.

The horses employed upon the above railroad were not so strong and heavy as those upon the roads shewn in Tables I. and II. The average resistance with the loaded carriages is about 70 lbs., and with the empty nearly 100 lbs., making a mean of 85 lbs. The distance traversed is four times every day, which is nearly twenty miles. In winter, (for about five months in the year,) they are only able to travel with three carriages. Though less than the other horses, they were by no means small or light, but what may be termed moderately sized. The resistance upon one part of the road, with the load, amounts to 342 lbs. ; but, as the distance is short, and the carriage has previously acquired considerable velocity, before it arrives at this part of the road, the momentum will aid the horse, in overcoming the resistance, for this short distance.

The average resistance overcome by the horses, in Table II., is 115 lbs., and in Table III., 85 lbs. ; taking the former as the effect of the largest horses, and the latter as the effect of smaller, we shall have the mean effort of 100 lbs., as the performance of moderately-sized

horses upon level roads, travelling twenty miles a day.

If the friction of carriages be reckoned at the 240th part of their weight, Table I., then the weight, which will present a resistance of 100 lbs. upon an edge railroad, will be 24,000 lbs.; as, however, the resistance of the carriages, in winter, would be greater than that shewn in the Table, we may, according to these experiments, take the power of these horses as equal to 112 lbs., the mean of Tables III. and IV., travelling at the rate of two, or two and a half miles an hour, or twenty miles a day; which, on a level railroad, would make the weight of goods conveyed equal to twelve tons.

Taking, then, twelve tons moved over the space of twenty miles a day, as the performance of a horse, the effect will be equal to 240 tons one mile; and, as this performance is effected at that pace, or velocity, which the horse inadvertently falls into himself, we may consider it his maximum effect. We have not, in the Tables, given the speed at which the horses travelled; that would vary much, according to the resistance presented in the different parts of the road; but the average velocity of Table I. did not amount to more than two miles an hour; and we are inclined to think, from attentively noticing the speed of the horses in the other, at various parts of the road, that the velocity with which they travelled would not be more.

The above was the conclusion stated in the second edition of this work, since that was written, it has been generally supposed, that this standard of the effort of a horse, was underrating his power; it must be observed, however, that the performance during one half of the journey, in each case, was, for the more powerful horses, 189 and 157 lbs. respectively; and, for the smaller horses, 100 lbs., making a general average of