rack, u 5, carries a pin, s, which when the strap has passed to the end of the driving cone, presses the rod, s, against the spring, 85, and overcomes its resistance. When in this position, if the rod, s, is moved upward, it comes against the projection, 82, elevating the lever, s 1, causing the arm, s 3, to move the rod, s 4, in the direction of the arrow, by which the strap, w, is moved from the fast to the loose pulley, and stopping the machine.

In order to secure an even distribution of the wear upon

Fig. 51. Self-acting stopping motion. Fig. 52.

M

Slubbing traverse motion.

imparted to the slubbing Fig. 52 shows the means A bar, v, contains holes,

the rollers, a lateral traverse is when it enters the back rollers. by which this is accomplished. vv, each of which receives two threads from an equal number of slubbing bobbins, on their passage to the back rollers, determining the place at which they enter the rollers. This bar is guided horizontally by the lever, v 1, which has its fulcrum at M, and is connected with L, sharing in the oscillation of the latter. Near the fulcrum, M, is a stud,

Both

v 1, whilst a similar stud, v 3, is fixed in the bar, v. of these studs slide in short slots of the lever, v 2, whilst the latter swivels on the pin, v 2. Through this connection the bar, v, is made to share the lateral movement of v 1, multiplied by the ratio of its leverage, moving horizontally through being guided. By this means the slubbing is moved to and fro between the rollers, by which the wear is evenly distributed over a considerable portion of their surface, thus insuring their greater durability.

The process of doffing, or removing the bobbins when full, is performed by turning the spindles backward by means of the wheel, w 2, on the driving shaft. The bearing for the top of the driving cone is next lifted by a lever which causes the strap to become slack. The shaft, u 1, is is then turned backward by the wheel, u 8, which action winds up the weight, u 4; the cone strap being by this means returned to the base of the driving cone, and q 1 brought back into its first position as shown in Fig. 1. The spindles are again filled with empty bobbins, when the machine is ready to re-commence operations.

To make the roving finer or coarser, the draught of the rollers has to be altered, which is effected by changing the wheels, c 2, and c4, Fig. 47. In proportion as the number of teeth in these wheels are increased, the amount of slubbing taken in will be greater, and the rove coarser in the hank. With a diminution the opposite effect will result. With lower counts, the diameter of the rove being increased, a fewer number of coils are required to form a layer; this necessitates an increase of the speed of the vertical traverse of the bobbin carriage, which is obtained by changing the pinion, f5, Fig. 46, for one having more teeth. When a finer rove has to be made, the substitute must be one of fewer teeth. With the production of a coarser rove, the velocity of the revolution of the spindles, and consequently, of the bobbins, must be increased, because the diameter of the layer of rove then put upon the bobbin being greater, its winding surface is increased, and therefore

the rate at which it will take up the rove will be such as to break the latter were it not counteracted by an acceleration of the speed in like proportion. Changing the ratchet-wheel, u 3, for one having a fewer number of teeth, secures this result; correspondingly, a finer rove requires a diminished number of revolutions of spindle, and a ratchet wheel of more teeth.

Such are the details of the roving frame. The intermediate frame which precedes it in the order of arrangement differs from it only in having its parts larger and correspondingly stronger. This difference necessitates a slower speed of the various parts, the proportion being when no wheels have been changed as five in the intermediate frame is to seven in the roving frame in all the revolving parts. As the rove produced on the intermediate frame is much thicker than that from the former, to prevent too frequent doffing and the loss of time consequent upon it, the bobbins are made larger, which necessitates stronger spindles and slower speeds to prevent excessive vibration. The diameter of the bobbin is increased, so that the winding on proceeds at the same rate as in the roving frame.

The slubbing frame compares with the intermediate, as the latter with the roving frame, the parts being proportionately larger and stronger. The speeds also are correspondingly slower; where the driving shaft of the former makes 250 revolutions, that of the latter only makes 220, the speed of the spindles being diminished in the same proportion. Often, however, the dimensions are the same, the differences being in these cases one of speed. mensions of the bobbins then are the same, though the coarser slubbing requires a ratchet wheel of less teeth in order to secure a corresponding acceleration of the spindle.

The di

The slubbing frame is fed from cans of sliver from the card, whilst the intermediate and the roving frame receive their supply of material from slubbing and intermediate frame bobbins respectively, which are contained in creels.

The foregoing illustrations of the roving frame we have

reproduced from a small work on "The mule spinning process, and the machinery employed in it," from which also the description has been condensed, the algebraical formula being omitted as unsuitable to a great extent for the present treatise.

:

CHAPTER VII.

DEVELOPMENT OF SPINNING.

Spinning its antiquity; conjectural origin; the first spindle. Definition of spinning.-The whorl; the distaff.-Spinning as described by ancient historians.-The hand wheel; its first appearance in Europe; in India.-The Jersey, or common hand wheel; its development from the spindle; the driving wheel, the wharve. Similarity between the European wheel and the Indian wheel; European wheel used for wool and cotton; process of spinning upon it.-The flax wheel, or the Brunswick and Saxony wheels; the flyer. The two-handed wheel; the traverse. The connection between the old and the new systems of spinning.-Cotton: antiquity of its cultivation and manufacture.-India, the birthplace of the manufacture; its extensive manufacture in that country.-Sterility of Indian invention. -Kay's inventions a stimulus to further improvements.-Widespread influence of inventions in the cotton trade.

SPI

PINNING is one of the most ancient arts, and in its beneficial influences, one of the most important. It is difficult to conceive what would now be the condition of mankind had this art not been invented. Nothing is known of its origin, for the earliest records in which it is mentioned, show it in the condition of advancement in which, after it became known, it remained, without further progress, for many centuries. Thus it may have had its birth centuries previously to its first mention in history. Only conjectures can be offered regarding its beginning, and these may be either far from or near to the facts. The same difficulty meets the investigator in connection with the material which formed the basis of the first experiments and earliest operations of the art. The writer, in another place, has ventured to suggest that the first spinner was a shepherd-boy, and the material used a few locks of wool. Reclining under the shade of a tree whilst his flock was