running parallel to the axis of the machine, and to the hinder end of which a short lever having a horizontal motion is attached receiving motion from the crank by means of a connecting-rod with a universal joint. This arrangement, Fig. 49, is, however, only practicable when the shaft is perpendicular to the axis of the machine.

The plane of oscillation is perpendicular, the main shaft above the sewing-plate parallel with the chord of the arc of oscillation and motion is transmitted by an eccentric groove. To the main shaft a cylinder is attached with a groove giving motion by means of a roller to a lever with perpendicular motion. Parallel to the axis of this lever is a shaft below the sewing-plate, to the front of which is attached the lever with the shuttle, the other end being connected with a small lever bent upwards, and connected with the end of the lever carrying the roller, Fig. 50. This arrangement can only be employed when the main shaft is perpendicular to the axis of the machine. Otherwise the lower end of the lever carrying the roller is joined to the shuttle-lever by a connecting-rod, Fig. 51.

The plane of oscillation is perpendicular, the main shaft above the sewing-plate perpendicular to the chord of the arc of oscillation and motion is transmitted by a crank. This combination can only be effected when the shaft is parallel to the axis of the machine. The crank-pin is attached to a horizontal lever by means of a connecting-rod attached to the hinder end of a shaft having the shuttlelever at the other end, Fig. 52.

The plane of oscillation is perpendicular, the main shaft above the sewing-plate perpendicular to the chord of the arc of oscillation and motion is transmitted by an eccentric groove. The construction, necessary in this case, is similar to that

shown in Figs. 50 and 51, substituting for the cylinder a plate with eccentric groove, Figs. 53 and 54.

The plane of oscillation is perpendicular, the main shaft below the sewing-plate, parallel with the chord of the arc of oscillation and motion is transmitted by a crank. The construction necessary in this case is similar to that shown in Fig. 49, except that the shaft is below the sewingplate. This arrangement cannot, however, be recommended, as the connecting-rod must be so much shortened that the friction of the joints becomes disproportionately increased.

The plane of oscillation is perpendicular, the main shaft below the sewing-plate, parallel with the chord of the arc of oscillation and motion is transmitted by an eccentric groove. If the main shaft is perpendicular to the axis of the machine, a cylinder with the eccentric groove is attached to it, by which a short perpendicular lever is put in motion, communicating with the hinder end of a shaft to the front end of which the shuttle is affixed,. Fig. 55. The lower lever-shaft can be also so shortened that both levers fall together, and the roller is attached to the shuttle-lever direct. If the shaft is parallel to the axis of the machine the cylinder with the groove in it puts a short lever moving in a perpendicular plane in motion. This is again connected by a rod having a hori-zontal motion with a corresponding point of the shuttle-lever by a hinge, Fig. 56. Dispensing with the connecting-rod the two levers become united, and the roller is attached direct to the shuttle-lever.

The plane of oscillation is perpendicular, the main shaft beneath the sewing-plate, perpendicular to the chord of the arc of oscillation and motion is transmitted by an eccentric

groove. This construction is similar to the foregoing, substituting for the cylinder a disc in which is the groove, Figs. 57 and 58. In this case the oscillating motion is frequently given to the groove, the rotating motion to the roller, especially when the groove is rectilinear.

The plane of oscillation is perpendicular, the main shaft below the sewing-plate, perpendicular to the chord of the arc of oscillation, and motion is transmitted by a crank. The crank pin is connected by a rod having a horizontal motion to a suitable point of the shuttle lever.

4. SHUTTLES WITH RECTILINEAR MOTION.

The shuttle is propelled, as before described, by the driver, which is attached, in the case of shuttles with curvilinear motion, to the end of a lever arm. With shuttles, however, having rectilinear motion, the driver generally consists of two parts, the one for imparting motion to the shuttle, the other, the so-called slide, serving as a guide. They are attached by means of screws. The section of the slide like that of the needle-carrier, to which it may be compared, varies considerably. The shapes most in use are shown, Plate IV., Figs. 1 and 18; Plate V., Figs. 1, 14 and 15; Plate VI., Fig. 9. The horizontal race in which the shuttle runs is either parallel or perpendicular to the axis of the machine; and as the main shaft can also be parallel or perpendicular to the axis of the machine, it must also be either parallel or perpendicular to the shuttle-race. The shaft can also be either above or below the sewing-plate, and motion can be transmitted either by a crank or eccentric groove, making in all eight varieties of construction, details of

which are, however, unnecessary, as those previously given may be readily modified to suit the rectilinear motion, it being only necessary to connect the lever, to which, in shuttles with curvilinear motion, the shuttle was attached, by means of a rod to the shuttle-driver slide. In many cases the lever may be entirely dispensed with by attaching the connecting-rod to the shuttledriver slide by means of a hinge, especially when motion is transmitted by a crank, as shown (Plate IV., Fig. 1; Plate V., Fig. 1). If the eccentric groove is used the roller is attached to a prolongation of the slide, which much simplifies the arrangements (see plate VI., Fig. 4).

5. LOOPER WITH LỌNG RECIPROCATING MOTION. The double thread chain-stitch looper of Grover and Baker reciprocates on a perpendicular axis, and describes almost a perfect circle. The following is the arrangement now generally employed for communicating motion to the looper: To the axis of the looper a small cylinder is attached, round which an eccentric groove runs and a roller attached to the end of the shaped needle-lever imparts a reciprocating motion to the cylinder. Latterly this arrangement has been somewhat modified by employing a nut instead of the roller, and giving the groove a screw form.

THE MECHANISM FOR IMPARTING MOTION TO THE

MATERIAL.

The material to be sewn is advanced at the completion of each stitch the length of a stitch. The sewing plate itself is constructed generally of cast-iron, less frequently of brass or steel; but the sewing hole is almost

invariably constructed in a piece of steel screwed into the plate, as the friction of the thread would otherwise be apt to enlarge the hole. This sewing-hole plate is made as thin as practicable; as the thinner this is the less distance need the lower mechanism be from it, and the shorter the needle. It is never more than in. thick, frequently only in. The hole must only be sufficiently large to admit of the free passage of the thickest needle with the thickest thread that is to be employed, as, if it is too large, the material is apt to be drawn down into it during the descent of the needle, and if too small, the thread is liable to fray and break. Machines for sewing thin materials, as shirt-fronts, &c., have a sewing-hole of 1" diameter, and the size increases according to the thread employed up to in. for sewing sail-cloth. The most usual sizes are between in. and

2

in. The sewing hole must be well rounded off, and is generally enlarged downwards so as to give play to the thread and cause as little friction as possible.

The material is held down by the so-called presser during the formation of the stitch, and at the completion of the stitch, is advanced by the feeder the length of a stitch. This feeder is roughened on its surface, and is situated beneath the presser and rising out of the sewinghole plate, advances, carrying the material with it. Sometimes the feeder is dispensed with, and in this case the surface of the presser foot is roughened, and it is so constructed as to make the necessary advance. The mechanism has therefore to be arranged for

I.-FEEDERS WORKING FROM BELOW.

The presser, in this case, consists of an iron rod, to the lower end of which a steel piece is screwed, called