required; the springs, n, pull this rod back, whilst the shafts, o o', make the same number of revolutions. The part, E, is covered with cloth and leather, and the jaws, G and H, are acted upon by the springs placed above them.

The two jaws, R R', compose the delivering nippers, and are respectively connected with two large levers, xx', which turn on their fulcrum, x, moved by the cams on the shaft, 0, which act upon the friction bowls, v, attached to the levers, xx'. After the action of the cam has been completed, the spring, m, returns the levers, x x', to their first position. The nipper jaw, R', is fixed to the lever, x, whilst the jaw, R, can slide up the rod, I', when the nippers are required to open, and descend again when they are to close. The delivery nippers are actuated by the cam, T, fixed on the shaft, o2, which turns on the bar, U. The shaft, o2, in its action makes the same and corresponding revolutions to the shafts, o o'.

The comb rod, P, is placed between the delivery and receiving nippers, and has an ascending and descending motion, pausing at the extremity of each. It It is actuated by the cam, M, and the frame, L, which slides in the guide bars, N. The comb rod, P, çontains from two to four rows of combs, which may be arranged to operate either together or in succession.

All arrangements being complete for work, the operation of the machine is as follows:-the delivery nippers, R R', seize and pull through the combs a certain quantity of cotton, which then passes on to the brush segment, s, of o2, and is passed by its revolution to the doffer, Y. The latter is arranged to oscillate, so as to receive the portions of cotton deposited upon it at regular and stated intervals. The receiving jaws in going back comb a length of cotton. When the combs descend they are cleaned by the revolving brush, Q, which takes and deposits the waste upon the revolving roller, q'. During the descent of the combs, the receiving jaws descend with the sliver to the central line,

and the delivering jaws return to the same position open, again seizing and closing upon the proffered cotton; the receiving jaws are then opened, and recede in order to be fed anew. The combs next rise and again pass through the sliver, when the preceding operations are repeated. The vibrating combs, z z', detach first the combed cotton, and second, the waste; the first named is formed into a sliver, and conducted between the four pairs of draw rollers, a a a a, and the delivery rollers, b b, thence to the coiler for deposit in the sliver can.

It is asserted that this machine does its work very well, both when dealing with long and short stapled cotton, getting through a great quantity, making a small amount of waste, and needing but little attention,—in these respects comparing favourably with the finisher carding engine.

L

CHAPTER VI.

DRAWING, SLUBBING, AND ROVING.

DRAWING: definition; its objects; doubling or combining slivers; minimizing irregularities; theoretical results.-Practical imperfections of doubling in past times; progressive improvement.-Extension of the process; causes of this.-The drawing frame: description; speeds of rollers; their action.-Details of construction.-Its development.-The electric stop motion.-Varieties of cotton.-Requirements in the drawing process.-Location of drawing frames; freedom from damp and draughts required.-SLUBBING: definition; description. Intermediate, or Second Slubbing, a repetition of the preceding.-ROVING: definition. -Roving frame description. -Differential motion of the spindles and bobbins in bobbin-and-fly frames, in the slubbing, intermediate, and roving frames; a nice problem in mechanics; Holdsworth's solution.The principle explained and illustrated; successive layers; the traverse; winding of each layer; diminution of coils.-Spindles of the three frames. Mechanism of the roving frame; connection between its parts; description; operation; the driving, roller, spindle, and bobbin shafts; jack in the box; the cones, method of operating them; the traverse movement; acceleration of speed. — Reversal of traverse and how obtained. Traverse of the slubbing. - Doffing.—Altering draughts. -The intermediate, and the slubbing frames.

S previously defined, in the process of drawing, several

attenuated to the dimensions of one. Every step in cotton spinning has a twofold object-the first being to carry the material a little further in the constructive process; the second, to eliminate or minimize the defects of the preceding stages. The constructive part of drawing is to further perfect the parallel arrangement of the fibres contained in the sliver, which is accomplished by the different velocities at which the rollers revolve, and the proportion of which will be seen subsequently; the second is to render the sliver more perfectly uniform in its dimensions, or in

the number of fibres contained in a cross section, than it is when delivered from the card. As shown in the preceding pages, there are various causes tending to produce irregularities, not only between one lap as compared with another, but also in the sheet of an individual lap. In the one case there are differences of weight-some being too heavy, others too light, whilst a third part may be correct; in the other, the sheet will, or may, be in one portion too thin, in another too thick, and, again, may be of the proper texture. A small irregularity in the lap will be increased in the sliver coming from the card just in the ratio of the draft. Thus, suppose that one foot of the lap sheet, through some defect in the working of the lap machine or neglect of the attendant, contains only two-thirds of the proper quantity of cotton, this in the card will be drawn out to, say, one hundred feet of sliver, which will only be of two-thirds the proper weight. Were this to be carried through the succeeding processes, until the yarn should be completed, the fault would increase with every successive draft or attenuation of the material, though the relative proportion would not be altered. If we assume that the design be to produce a 40$ yarn, under this supposition the resulting part containing the fault would be 60s, thus presenting the serious difference of twenty hanks. Error on the opposite side, in which the lap is too heavy, would produce defects quite as serious in making the yarn too coarse. This, however, rarely or never occurs in actual working, as experience has long ago demonstrated the necessity of doubling and drawing, by which its possibility is prevented. The parallel arrangement of the fibres in the sliver as it comes from the card is very imperfect, and must be improved. This could not be accomplished satisfactorily were the single sliver to be drawn, as the attenuation or reduction of "the grist," as the dimension is called, would be far too rapid, and the object would be unaccomplished when the sliver had been reduced to a fine roving. Therefore it is that doubling is resorted to, which enables