The drill is used when it is desirable to sow seed in rows at intervals from each other, so as to give room for the plants to grow, to free them from weeds and admit air, light, and moisture; it is a machine which contains the seed for sowing, and at the same time makes a series of furrows to receive it. There are a great many varieties of drills, but they act upon the same principle, namely, that of a cylinder, taking up and pouring small portions of the seed into funnels so arranged that they shall follow a set of small coulters forming furrows in the ground, into which the seed falls; the drill is generally followed by a bush-harrow which covers up the seed. Some drills have two compartments, one for containing manure, the other for seed; the manure must be dry and pulverised, such as ground bones, ashes, &c., which arrangement allows the seed and manure to be both drilled together, so that the manure shall only be applied where it is wanted. The cut represents this machine; A A are portions of the cylinders which are turned round by toothed wheels attached to the ordinary wheels of the machine, and which can be put in or out of gear at any time, so as to stop the action of the drill; B B represent the funnels into which the seed is poured, and C C the coulters which cut the furrows for the seed. These coulters are pressed into the ground by means of iron weights attached to the ends of levers joined to them, and which can be regulated by small chains. ENGINEERING WORKS. RAILWAYS. Illustration: (‡ LOCOMOTIVE AND TENDER.) The great advantage of railways over ordinary roads is the diminished friction, which is produced by the wheels passing over the smooth iron instead of rough stones. It was found when iron rails were first used, before the introduction of locomotives, that the horse-power requisite was diminished to one-fortieth; for instance, ten horses on a railway could do the work of four hundred on a common road, this being the case, and the great power of the locomotive engine being superadded, there can be no wonder that the difference of the rate of speed between the train and the wagon should be so great. When it has been settled what general direction the railway shall take, it is then to be determined whether or to what extent the elevations or depressions that may occur can be conveniently overcome, so that the line may take a straight course, or whether the road shall go out of the straight line, and how far to avoid them. The route it should therefore take ought to exactly balance the objections to each extreme, that is the expense, &c., of going straight on through hills and over valleys on the one side, and the increased distance and consequent loss of time which a winding track would cause to the transit on the other. Illustration: FIG. 1. (‡ TERRAIN SCHEMATIC.) Illustration: FIG. 2. (‡ TERRAIN SCHEMATIC.) Illustration: FIG. 3. (‡ RAIL TYPES.)