by Robert Beatson, Esq.—This object is effected by fixing between the other wheels a protector, or small roller, or broad wheel: the circumference of its upper part should be about 112 inch beneath the axle-tree, while the lower one ought to be at a similar distance from the ground. Such roller must be secured to the axle-tree, so as to be able to support the whole weight of the carriage, in case the principal wheels descend into any deep ruts. The size of the protector varies according to the proportions of these wheels; but Mr. B. observes, that two feet in diameter will be sufficient for single carts; and that double carriages, or waggons, will require it to be rather larger and broader. By thus elevating the roller a little distance above the lower surface of the wheels, the latter will, on good roads, support the weight of the load; and, if the middle or horse-path be firm, they cannot sink into old, or form any new, ruts; because the protector will roll in the middle, and thus afford an easier draught to the cattle. The additional weight of the machine, if it be properly constructed, Mr. Beatson conceives, will be inconsiderable; when compared with the utility of such contrivance, and the great reduction in the expence both of making and of repairing roads.—A more comprehensive account of this invention, the reader will find in the work above cited, where it is farther illustrated with an engraved figure.
Roan-tree. See Quicken-tree.
Roasting. See Cooking.
Rob. See Elder; vol. ii. p. 219.
Robin-Red-Breast. See Red-breast.
Rock-salt. See Salt.
ROCKET, or Brassica Eruca, L. an exotic species of the cabbage, which was formerly cultivated to a considerable extent in gardens.—It is divided into two varieties, known under the names of the Wild and Garden Rocket.—This plant is propagated from seed, which is sown early in the spring: it flowers in the month of June. When used as a principal ingredient in summer salads, it is, on account of its pungency, always eaten together with endive, purslane, or similar cooling vegetables.
With respect to its medicinal properties, the rocket is aperient, and expels flatulency. Its seeds are remarkably acrid, resembling mustard in flavour; for which spice they have often been used as a substitute.—According to Bradley, it is an useful vermifuge; and, when boiled, and applied externally, is said to remove spots from the face.—Böhmer informs us, that both the seeds and flowers of this herb may, in times of scarcity, be converted into bread.
ROE, in ichthyology, denotes the eggs or spawn of fish.
The roes of male fishes are usually denominated soft roes, or melts; as those of females are known under the names of hard roes, or spawn.—Both vary in size, according to the fish from which they are obtained. Those of cod, for instance, when pickled, are greatly esteemed at the tables of the luxurious. Such rancid food, however, ought not to be eaten by the invalid, the convalescent, or otherwise debilitated; as, on account of its crude nature, and peculiar acrimony, it is very apt to cause indigestion, with all its numerous evils. But, if the epicure cannot abstain from dishes of this description, he
