CART. The drag - cart without wheels, which is used in some mountainous districts, is one of the simplest contrivances for trans porting heavy weights. It consists of two strong poles, connected by cross-pieces fixed at right angles to them, the ends resting on the ground. The other ends of the poles form the shafts for the horse to draw by. The Irish car may be considered as the next step to wards a better construction. This car consists of a bed or platform and two shafts. The wheels, in the simplest form, are round disks of wood, fixed on a square axle of wood at the distance of three or four feet from each other. To the under part of the bed of the cart two blocks of wood are fixed, which raise it so that the wheels may go under the cart, and in these blocks are two round holes to admit the ends of the axle. This is the simple old Irish car. The only difference in the construction of the most improved modern cars is the substitution of neat wheels and iron axles for those de scribed above, and a railing or box fixed on the platform.
The common cart differs from the car in that the body rests on a fixed axle between the wheels, which turn upon the axle by means of boxes in the centre of the naves. The sim plest cart is that used by carriers in France and Germany. It consists of two strong poles of ash or beech, resembling those of the drag cart described above. One end forms the shafts, and the whole is equally poised on the axle. The wheels are often nearly six feet in diameter, and narrow at the tire ; they are slightly dished, but run nearly perpendicularly to the road. On these carts very great weights are transported, so as to require five or six horses to draw them. Where the roads are level and hard, waggons are much to be pre ferred to carts ; but in hilly countries and bad roads carts have many advantages. For agri cultural purposes various kinds of carts have been invented. The capacious tumbril for
carting earth and dung, with broad wheels to prevent their sinking in soft ground, is too generally known to require description. The light Scotch cart, drawn by one horse, is justly considered as the most advantageous for tran sporting earth, lime, or dung, especially in hilly countries. It is low and short, so that the horse draws very near the centre of gravity; and there is little power lost by obliquity. It is made to carry hay and straw by means of a light frame, which is laid on it, and projects over the body and the wheels in every direction.
To avoid the weight resting on the back of the horse, carts have been invented with three wheels, the small additional wheel being made to turn in front. The addition of springs to carts and waggons is a very great improvement, and should be adopted in every case where they are much used on the roads. The addi tional weight of the springs and their cost are greatly overbalanced by their advantage : they lessen the draught, and, by preventing jolting and shaking, add to the durability of the vehi cles.
Our agricultural machine makers have made many improvements in carts within the last few years. Croskill's one-horse cart is formed to carry a considerable load, with less weight on the horse than ordinary carts ; it is now much used in agricultural counties, to carry (say) five quarters of wheat 10 or 12 miles to market and return with a solid load of 30 cwt. Among other varieties are the Norwich cart, the Norwich pair-horse waggon, the Exeter cart, the Scotch cart, the Newcastle cart, (be. Many of these carts are now provided with Croskill's patent wheels and axles,made wholly by machinery, and consisting principally of iron.