nature with the greatest attention to the combination of agility and strength. He is, by art, applied to the purposes of riding or of draught. Our present inquiry refers to him under the latter description.

As horses are the power most commonly applied to overcome agricultural difficulties, it is necessary the mechanical formation of these noble animals should first be considered. A horse's limbs are a system of powerful levers, actuated by muscles of propor tionate strength and wonderful contrivance! By these he can carry near 800lb. on his back, draw upwards of 80lb. for hours together, and some of his species have run near a mile in a minute! For beauty, he may be considered as the paragon of animals; and for spirit and courage, incapable of fear, or giving up what he contends for.

The slope of his shoulder, making an angle with a perpendicular to the horizon of about 14 or 15 degrees, shews that the horse was not designed to draw horizontally, or as horses do in a team; for, though it is unnoticed, his collar is drawn up against his throat, and obstructs his breathing: if his collar lie inclined on his shoulder, his line of draught should be perpendicular to it, and consequently incline to the horizon in the aforesaid angle, thus:

part of it; acting like a theorist in mechanics :

C

a is the centre of gravity of the horse; from a to c is the acting part of the lever; from c to b the resisting part; therefore, in thrusting out his hind legs he lengthens a c, and diminishes c b. The muscles of his hind legs add to the power of his weight; but his fore legs are of little use to his draught; they prop the forepart of his body, and by their action lift up his centre of gravity, so that by its fall its weight may act upon obstacles and resistance; for in all difficult draughts a horse has an undulatory motion, rising and falling every step; and it is by the falling part of it, that he overcomes the obstructions to his draught: hence the use of heavy horses for great loads.

If the horizontal line a have the inclined line of draught drawn from the horse's shoulder at an angle of 14° or 15°, it would extend to the bottom of the wheel, as the dotted line c does. This is certainly too low for a line of draught. Therefore, in carts, if the slope be not more than 8 or 10 it will be found more convenient, though less mechanically powerful. This manner of draught, from five or six inches below the axle, has been practised repeatedly with

success.

I therefore apprehend that a four-wheel carriage drawn by the shaft horses at an angle of 10, 12, or 14 (according to the size of the horses) are the best angles, both animal and mechanical, that a horse can. draw in.-But as horses in a team must draw horizontally, the shaft horses will have a portion of the weight drawn down on their backs by the pul! of the fore-horses; because all lines of draught, if crooked or angular, have a tendency to draw into a straight line.

Where another horse precedes that attached to the body drawn, we have to

guard against the effect of this tendency; for if the line of draught of the nearest horse be adjusted with the nicest accuracy, yet the distance of the one in advance, vacates every reference to the principle of gravity, as attached to him, and ren

ders a different line of draught indispensable. As this is of the greatest consequence to many persons whose vehicles are drawn in this manner, we have copied the figure by which the nature of this action is shewn.

Fore Horses

This figure also shews the relative proportions of the height of the wheels to each other, and to the horse by which they are drawn. But it is evident, that many considerations may render variations desirable; such as, the conveniency of employing horses of different sizes, occasionally the necessity for adopting the forms and constructions of carriages to narrow and crowded streets, to different motions and attitudes, as turning, backing, &c. and to other conveniencies. Mr. W. thinks that the wheels of carriages having but one pair should be about 5 feet 4 inches in height: then forming the line of draught to 12° or 14° (agreeable to the shoulder of the horse), it will follow that the fore wheels of carriages having two pairs, must be much smaller, and this, which he observes is quite necessary for easy turning, may be done without much harm to the draught.

The machines that are usually drawn by horses may be classed under three kinds: coaches, carts, and waggons. The first are fitted for speedy conveyance, and are supposed to be laden rather with passengers than luggage: the second are laden with luggage in small quantities: and the last are understood to be heavily laden with goods of a ponderous kind. The principles on which these machines are constructed are of great consequence, in this inquiry; but, we shall place first the principle on which they are, or ought to be, laden, as being most ordinarily too little attended to in practice.

OF WEIGHT OR GRAVITY.

Weight, or gravity, is the tendency of any body to fall in a direct line, as the nearest way, to the centre of the earth.

Let these two figures represent two carts laden with corn, one on level ground, the other on a declivity; a. the centre of gravity, and a. b. the line in which the loads would fall. In one, there is no danger, because the line of direction falls within the supports: the other must overset, because its directions fall beyond the supports.

In loading waggons, it is necessary that the centre of gravity of the load should be nearer the hind, than the fore, wheels. In carts, the centre of gravity of the load should not be directly over the wheels, but a little in clining towards the horse; as his powers, or momentum, will be increased by a portion of the weight on his back.

It is a law of nature that the centre of gravity endeavours to get as low as it can, and always beneath or behind the power by which it is dragged or suspended. If I hang a chair by any part on my finger, its centre of gravity will always settle under my finger. If a harrow be yoked to a horse by any part, its centre of gravity will get behind that part when the harrow is put in motion. Hence the absurdity of out-riggers; of horses drawing on one side of the line of direction, wasting their strength and wearing the car

riage; drawing in a small circle, as in threshing machines, &c.

extreme

The absurdity of placing any undue portion of weight at any either side of the direct line of draught,

on

is shewn to ocular demonstration in these figures it is evident too, that elevating any undue portion of weight above the direct line of draught is not without danger these two absurdities united, render accidents, when they happen, so fatal, as to cost the lives and injure the limbs, of many hundreds of persons every year. The fact is, that the nearer Loth weight and draught are kept to a true and direct line, acting most immediately on the centre of gravity, the less danger and

the less toil is incurred.

But, weights of all kinds are not felt alike by the power that draws them: there is in live weight a lightness if compared with dead weight: and by mechanical inventions, the comparative gravity of dead weight, also, is considerably diminished.

SPRINGS.

Springs were, in all likelihood, first applied to carriages, with no other view than the accommodation of travellers; they have since been found to answer several important ends. They convert all percussions into mere increase of pressure; thus preserving both the carriage and the materials of the road from the effects of blows; and small obstacles are surmounted, when springs allow the frame and wheels freely to ascend, without sensibly moving the body of the carriage from its place.

Springs, as they regard the ease of draft, in some cases lessen the resistance to the horses in a higher proportion than ten to one. Now, although springs, such as those applied to coaches, cannot be usefully employed for heavy waggons, yet the timber of a waggon may be so adjusted as to yield to sudden shocks on rough roads or pavement.

Indeed, whoever considers the subject even in a popular manner, must perceive, that the springs ease the horses as well as the rider; for, whatever jolting motion the latter receives, is communicated by the rising or falling of the carriage going over obstacles; the force of the horses alone produces this motion, and whatever lessens it lightens the horse's labour.

If sixteen people outside and inside of a stage coach are jolted upward even one-third of an inch in travelling one yard, it will require a constant force of twenty pounds to communicate so much motion to the carriage. The whole friction of the axle-trees does not obstruct the motion of the carriage much more than this slight vibration.

Now the springs commonly used diminish the resistance occasioned by such jolts above half, so that they are as advantageous as any

contrivance that would lessen the friction of

the boxes upon the axle-tree in proportion of

two to one.

re-action, in preserving the momentum, or Springs are extremely serviceable by their vis inertia of a carriage.

If a loaded carriage without springs sinks into a hole, the momentum it possessed, is received by the road, and destroyed; and the moving power must overcome the increased resistance. If the load is upon springs, they receive the impulse, and restore it with little diminution; they also prevent the load being injured. Since the receptacles' for luggage in stage coaches have been joined to the body, and the whole placed upon springs, the luggage has suffered little injury compared to what it used to do. The proprietors of the Shrewsbury coach have paid, in the course of a twelvemonth, before the improvement took place, £600 for goods damaged in the carriage. Springs, similar to those placed upon the fire engine carriages, would be equal to the load of a waggon, without increasing the height.

With regard to stage coaches, there are two circumstances which require particolar consideration, the height of the coach, and the manner in which the load should be disposed. Unfortunately these are left to the decision of the proprietor, or driver, or porter, none of whom are competent to the task, and they are obstinately bent, on preferring strait perches, and an elevated body, without any thing conclusive in practice or experiment to warrant such a preference; that either can affect the draught of the carriage or cattle, is too absurd to demand refutation.

As to the loading, it is nothing but daring ignorance, in support of pecuniary advantage, that bears these men through their determi nation, in carrying such weights on the tops of coaches, as are every day seen going out of town, and coming in.'

But the evil of outside passengers and packages, attaches more to the double coaches, than the single-bodied ones, for whereas the single coaches carry six outside passengers, the double ones will carry ten; and whereas the single coaches can carry but a short range of packages, the double one will carry a much longer range, and hence make a double disadvantage as to oversetting; for both the double and single coaches are precisely the same as to the lateral distance of the wheels.

There is another circumstance which attaches great casualty to the safety of passengers, and that is the absolute uncertainty as to the number of inside passengers, hy which the centre of gravity is very variable;

and when all the passengers are on the top, as is very common in fine weather, nothing but smooth and even roads, or great skill and attention in driving, can prevent oversetting. A total proscription should stand against any other sort of load on the top tha pas-, sengers, for this son, that when a coach shall neel to one side, niere instinct will induce the passengers to incline the contrary way, which is not the case with packages.

Some regard oght to oe had to the weight inside. There! be some difficulty in assigning the number of outsides, when there are none within; but it would be better there should be no outsides at all, when there are none inside, than suffer the least encroachment a positive rule once established.

We must now consider the effect of these princles in practice. The legis lature has enacted various regulations and prohibitions against such abuses.

Stage coaches carry four, six, or eight inside passengers.

The mails carry two outsides: and the post coaches, according to 46 Geo. III. with four horses ten, besides the coachman and guard, in winter, and twelve in summer. could these numbers be reduced.

Nor

The whole body of the carriage is now hung on horizontal springs, coach-box and hind boot, nd such convenience is now made for the outsides, that it can carry with more ease and safety twelve outsides than formerly six. The seats for the twelve are thus distributed one with the coachman, four in the front, four behind, and three in the chair

behind.

:

The luggage is carried in the fore boot, and part in the hind, and sometimes, it is tied on the middle of the roof, where they generally contrive to put millinery goods and the lightest articles. The coaches being now made more roomy in the fore and hind boots, to hold the goods.

According to the original plan, mail coaches were only allowed to carry four inside passengers, and one outside passenger, besides the coachman and guard. The Post-Office

now allow one to ride on the coach and one

with the coachman; and in some country places they are allowed to carry four outsides besides the coachman and guard, as a convenience to the inhabitants in remote parts of the country, and an inducement to persons to undertake the conveyance of the mails, and to furnish horses.

They may carry any quantity of luggage in the boot, and of any weight; specie is often carried in that way, for the public service; the mail-box behind is exclusively for the carriage of the mail.

The weight of the carriages and their load

in London is not limited, therefore they carry greater loads than would be allowed on any country road. The ponderous weight of London waggons much injures the houses by the continued vibration. This vibration is greatly owing to the streets being paved, and before the vibration occasioned by one carriage has ceased, it is freque strengthened by the stock of another load. These circumstances expedite the decay of the houses, and much injure the pavement, which of course is constantly under repair during the day time, to the great inconvenience of passengers and of commerce.

selves we learn are, about,

The weights of these machines them

An Irish car, not 3 cwt.
A Leith cart, about 7 cwt.
Three-inch (breadth of wheel) carts, 9 cwt.
Six inch carrs, about 18 cwt.

The common six-inch waggon, about 22 cwt.

The common nine-inch waggon, from 30

to 40 cwt.

Sixteen-inch waggons, upwards of 55 cwt. A gentleman's carriage, 18 cwt.

WEIGHTS CARRIED.

The goodness of the roads in Ireland is principally owing to their one-horse cars; but the general run of the weight of their loads seldom exceeds 10 cwt. Four cars of 13 cwt. do considerably less damage to the roads than any one-horse cart whose weight amounts to

30 cwt.

ROADS.

memories could recollect pretty far back into the last century.

Roads in Scotland.

About fifty years ago the late Marquis of Downshire was travelling through Galloway, having labourers with their tools attending his coach, which was then a necessary part of the retinue; but notwithstanding that precaution, his lordship and his family were obliged to send away their attendants, and to pass a night in his coach, upon the Corse of Slakes, a hill three miles from the village of Creetown. That event was the cause of consultation between his lordship, and the late duke of Queensberry, and other noblemen and gentlemen in that neighbourhood; and forty-seven or forty-eight years ago, colonel Rixon was sent by government, with a large party of soldiers, to make a road through these counties and the county of Dumfries. Soldiers were kept at work on that road for nearly thirty years. I was frequently with them, and soon began to observe errors in the execution of the work, as well as in the direction, which was without any survey. The errors arose chiefly from ignorance, but frequently from the mistaken selfishness of the proprietors, who objected to the opening of particular inclosures; and also from the tricks of the soldiers, in regard to the execution of their work, and the neglect of the officers; and sometimes from small bribes given to the inferior overseers, and to the soldiers.

The necessity of survey's being carefully made, and well matured, also, before a road is formed, has never been properly felt, in this island. For a short space, the importance is not thought to be great : but, on extensive lines of distances, the judicious application of skill is likely to afford extremely beneficial results.

Surveys.

The best principles of directing and making of roads, are chiefly that they be made in the shortest direction, level, hard, smooth, and dry, and of solidity and width sufficient for the trade that may be expected upon them. It is indispensably necessary, that very exact and carefully taken levels, plans, and estimates, be made by intelligent surveyors, previous to the work being commenced.

Surveys are as necessary for roads, as for canals, and railways or train roads; and the waste of money, and the misapplication of labour, that is now going on in the British isles, upon roads that have not been properly surveyed, is immense. A survey of the road from London to Ireland, from the point where it should separate from the road to Edinburgh, and to proceed by Carlisle to Dumfries, would be of great advantage. The

road to Bath also, fine as it is, might be greatly improved by an able engineer, and the advantage would be seen by great numbers of persons who may not have an opportunity of examining the other lines. It is certainly right, to make general surveys at once, because partial improvements may be lost when general improvements shall afterwards be made; and steep hills remaining in the roads of one county, would prevent, in a great degree, the benefit that the improved roads in another county, would otherwise afford.

The like error is probably to be lamented throughout Great Britain; it has of late been rendered more strikingly obvious, by the levels taken for navigable canals. On their banks we shall probably (ere long) see our turnpike roads constructed, especially in uneven countries. This plan would be highly advantageous to save draught and time, and to procure a supply of materials for the roads, in every part, without the trouble and expense of any land carriage.

Necessary Attentions.

Three regulations are found to be particu larly beneficial :-first, the drains along the roads ought always to be within the fields.there ought always to be an earthen bank, about three feet high, along the sides of the roads, which is the best and the cheapest means for protecting carriages, and every thing else, from falling over at dangerous places; and, thirdly, when a road is conducted along the side of a hill, it ought always to be sloped towards the hill, at about the rate of one in twenty-four; this prevents ice from being formed on the road; assists the bank in directing the stream of the wind, so that such roads have never been shut up with snow; and is another security from danger along the edge of precipices.

It would be an advantage for all waste land on the road side to be inclosed, and, as much as possible, to avoid short turnings and deep ditches at the side.

Boughs hanging over the high roads should be cut off, and the hedges kept trimmed; the roads would then receive every benefit of the air and sun, of which they are often deprived from the above causes; they are almost always slubby.

These attentions also would be helpful in preventing robberies and other depredations committed on travellers by night, where there is harbour for beggars, gypsies, and other idle characters; which would not be the case if the roads were made as straight as possible, and a proper fence on each side.

Drains.

Where drains cross the roads, instead of forming hollows dangerous from the sudden jolts they occasion, they should be sunk, and