SUGAR exists in every part of plants. It is found in the roots, as those of the carrot and beet root ; in the stems, as in the birch, the maple, some palms, and especially the sugar cane ; in the leaves, as those of the ash ; in the flowers, the fruits, and seeds. But the sugar which now forms a very extensive article of commerce, and may be considered as a necessary of life, is entirely obtained from the juice of the sugar cane, which is chiefly cultivated in the East and West Indies, by planting cuttings of it in the ground in furrows, dug parallel for that purpose ; the cuttings are laid level and even, and are covered up with earth ; they soon shoot out new plants from their knots or joints; the ground is to be kept clear, at times, from weeds, and the canes grow quick. When the plants have arrived at their full growth, which, in the West Indies, is in the course of twelve or fourteen months, they are cut down and bruised by means of machinery.
The sugar mill is composed of three rollers of an equal size, and all armed with iron plates, where the canes are to pass between them ; only the middle roll er is much higher than the rest, to give the larger sweep to the two poles to which the horses are yoked. This great roller in the middle is furnished with a cog full of teeth, which catch the not ches in the two side rollers, and force them about, to bruise the canes, which pass quite round the great roller, and come out dry and squeezed from all their juice, which rune into a vessel or back under the mill, and is thence conveyed through a narrow spout into the first boiler.
Sugar mills are, however, differently constructed, but in Plate Sugar Mill are the plan and elevation of one made by Mr. Thomas Rowntree, Blackfriar's Road, Southwark, and sent by him to the West Indies.
A B and D E (fig. 1 and 2.) are four ground sills,crossing and halved into each other; on the points of intersection four uprights are framed F F F F; these are connected at top by cross pieces a a b b; e (in fig. 2.) is another similar framing between the uprights.
Three blocks of wood are fixed cross wise between the beams e e, and similar ones cross between the upper ones a a, to support the bearings for the three rollers, f g h ; these rollers are made of cast iron, and turned in the lathe ; they have cog wheels at their upper ends, that they may all turn together ; the axis of the middle roller, g, is much longer than the two others, and at the upper end is square ; a strong wooden cross plate, with iron, i k, is fitted on it ; some dis tance above this, it has a square piece of iron, n, fixed on its spindle ; the long le vers, In by which it is turned, are bolt ed at their ends to the piece of iron n, and to the ends of the wooden cross i ; the harness of two mules is made fast to the end of each lever, by hooking their traces into the rings at the end of the le vers. In this manlier the middle roller is
turned round, and, by the cogs, the other two by the side of it. The pivots of the rollers are cylindrical, and each turns be tween six friction rollers, which traverse in a frame made fast to the cross beams, between a a and e e; the outside of two of these beams slide in rebates cut in the beams a a and e c, and can be moved up towards the middle rollers by wedges t t t t; the weight of each roller is supported on three friction wheels below its lower pivot. The construction of a set of these fric tion wheels is shown in figs. 3 and 4. Fig. 4 is an elevation, and fig. 3 a plan ; a (fig. 4) is the end of the pivot ; below this it is turned smaller, nearly to the size of the small circle in fig. 3. so as to leave a square shoulder ; b is a circular brass plate, fitted upon the small part of the pivot, and resting against the shoulder; d is another similar plate supported by a block of wood, seen in fig. 2, laying on the ground sills 1) E (fig. 2;) the small part of the pivot comes down beyond the plate, b, and enters a hole through a thick iron ring, e, (fig. 3;) this ring has the three arms projecting from it, which serve as pivots to the three friction roll ers im n ; it is upon these rollers the up per plate, b, and the weight of the great roller rests: as the pivot, a, and the up per plate, 6, turn round, the three rollers roll round upon the under plate d; the iron ring, e, has no share in holding the weight, its use is only to keep the three rollers in their places, and in the same manner the small part of the pivot keeps the ring in its place.