The machine acts as follows :—The stems to be operated upon are placed on the table, and the top ends are first put between the grooved feeding-rollers, and thus crushed and divided longi tudinally. As the stems_ pass between the grooved or fluted cylinders, they travel on to the counter-beater, where they are submitted to the action of the rakes of the top beater, which crushes the wood into fragments. The leaves, straw, and refuse become engaged between the two beaters; these, by means of their reciprocal gearing, and the combined action of the rakes and spring-blades, detach the fragments of wood, refuse of epidermis, and gummy matter, from the fibres. The stems, already in a fibrous state, still pass between the coated decorticating-cylinders. Travel ling onward, between the scraping-cylinders, they are scraped above and below lengthwise ; and passing between the friction-cylinders, and across the friction-plate and endless grooved table, they are cleansed, completely softened, and brought into a state ready for combing. Finally they are passed through a cylinder,-and then fanned. The machine requires 1 11.-P., and turns out 500-600 lb. clean fibre daily.
Figs. 643 and 644 show plan and longitudinal section of a Roland machine adapted to hand power, and suited to operations on a small scale, the dried stems being dressed on the field. The stems are introduced between the fluted iron crushing-cylinders a, adjusted by springs I to suit the thickness of the stems. These cylinders a are provided with triangular rings of varying depth, and are put in motion by means of cog-wheels. From a, the stems pass between the wooden beating rollers ij, provided with pointed iron bars h, to each of which are affixed two blades lm; blades 1, being of iron or wood, are inflexible, and break the stems against the cylinders a; while blades m, of indiarubber covered with steel, or of steel alone, are flexible and elastic, and act as scrapers for the removal of the epidermis and woody refuse. The beating-rollers revolve 3-5 times faster than the crushing-cylinders, and may be adjusted by the set-screw g. Each rake of the beating-rollers carries a comb p, to assist in removing the fragments of refuse from the fibre. This machine is capable of turning out 150 lb. clean fibre daily.
Moerman-Laubuhr's system of retting, breaking, and cleaning has attracted some notice on the Continent. The cut plants are laid in retting-pits, measuring 2 cub. yd. in contents, and lined with cement ; here they are kept down by pieces of timber, held by cramps at each end. Witb the object of hastening the operation, to every 1000 lb. of stems, are added 5 lb. flowers of sulphur, 5 lb.
pounded and sifted coal, and 5 lb. ground chalk, carbonate of soda or potash, or clay. At the end of 5-6 days, the retting is finished ; the bundles of stems are then taken out, partially opened, and set up in conical stacks to dry ; when dry, they may be stored for any time, without injury.
The breaking and cleaning of the fibre are performed by three distinct apparatus. The first is a powerful crusher, with four pairs of heavy iron rollers ; the second has two pairs of heavy fluted cylinders, to which a differential movement is given, thus breaking up the woody matter previously flattened and split by the crusher into atoms, three-fourths of which fall out below the cylinders. The third apparatus is a vat, 8 ft. in diameter, and more than 3 ft. deep. In the centre, revolves a vertical iron axis, supported by steel collars, and carrying 14 strong iron arms or beaters; these are driven at high speed, and strike with great force upon the fibre, which, in a partially charred state, is introduced by handfuls, through six slits or indentations in the side of the vat. The woody matter is thus effectually removed, while the suppleness of the fibre is increased, and no harm is done to it. A ventilating fan, fixed above, carries away all the dust. The complete apparatus is capable of dealing with 1-2 tons of stems daily, yielding 400-800 lb. of fibre ready for spinning.
Laberie and Berthot's machine for de corticating the green stems of Bcehmeria is shown in Fig. 645. The machine being set in motion, a workman takes the stems in both hands, and introduces them, top downwards, into the angle formed by the cord a, and the grooved wheel b, at the point c, where they are held by the cord. The stems, whose tops are brought to the concave cylinder d, by the iron rod e, are carried between the cylinder f armed with knives g, and that part of the cylinder d touching the knives g. The stems are here deprived of all the woody matter which is mingled with the fibres, and arrive cleansed at h, where the cord leaves the wheel. At the extreme end of the stems, there is always a non-decorticated patch, corresponding to the point at which they are held by the cord ; this is usually cut off, or it may be passed again through the machine. Several of these machines are already being used in Algeria. Each ma chine is capable of decorticating 75,000-80,000 stems per diem. Before feeding the machine, it must be worked empty for some time, to bring the cylinders to the right adjustment for the reci procal action of the knives. If the latter are too sharp, they must be rubbed dawn with a brick. The cord must always be kept strained tight.