2d Motion. This is the circular revolution which the mesh-frame takes upon its own axis, carrying with it the attendant apparatus in order to form the ring. For the principle of this, of which something has been already said, reference may again be made to Drawing 1st. Fig. 1 and 2. In Fig. I. it will be obvious that the cord which passes round the pulley at F will turn it either from right to left, or vice versa, every time that the shaft I is elevated or depressed. This shaft may be constructed as an oblong frame placed horizontally along the whole machine, and moveable on ecntrc directly behind the spindle A. Then, if that pat t at the 1( ft hand which pears elevated IA depressed, the other end at the light ill and the whole spindle will turn round one, one ;Ind it (inart( r, or one and a half turns, as may be most convenient, and by sinking the right again, it will revert to its present ; these motions may be convenient ly girt ii by two treddles like those of a weaving loom. Thus the circular motion of the twine to form the ring may be produced.
3(1 Motion. Of this something has already been said, it being entirely analogous to the first motion. Both bob• bins are to be lifted by a shaft and hooks, to bring them upon this' upper spindle. The whole is then to he moved until the bobbins arc over the centre of the ring, when they may be let down and tightened to fii•m the knot This being dune, the spindle returns to the outside or the ring. The motions are seen very plainly in Fig. 3., both being effected merely by moving the shaft 0, which. may either be done by the hand or foot, as experience may show to he preferable.
4th :\ lotion. The knot being drawn tight, is to be lifted off the points at C, (Fig. I, 2.) which may he clone by raising any ()I' the directing shafts, without any addi tional apparatus. The receiving beam being then moved one notch, the operation is completed. The simplicity of these motions, and the smallness of their number, must be eu idently advantageous to a practical machine, whether wrought by the operator, or put in motion by mechanical pourer. In particular arrangement for the former of those plans, the most efficient practical rule always is, to employ both the hands and feet of the ope rator, allowing as much as can be done without the incon veniency of too frequent shifting to be performed by the feet. The obvious reason of this is, that the less that the hands are employed in the production of motion, the more they will be at liberty to remove or correct casual impediments, without retarding the operation.
It will be obvious that what has been written is rather to be viewed in the light of general and leading princi ples, than as a detailed description. Nothing could be
farther, however, from the writer's intention, than to pass any thing in a cursory or superficial way for the purpose of concealment. Experience has convinced him, that in the description of infant and speculative inventions in mechanics, it is always more safe, and certainly much more candid, merely to state principles of action in a general way, than to incur the risk of misleading others, by laying down, in a certain and didactic form, what has not yet been proved by the only infallible criterion, viz. the results of actual trial and practical experience. In the present state of the invention, what remains may be confined to general and miscellaneous remarks, and what further description is necessary to convey such an idea of the drawings as has not hitherto been given.
Figure 7. exhibits a general view of a profile elevation of the machine as viewed from the right hand. The posts are at AA ; the top rail of the framing at 11 ; the receiv ing roller at C ; a section of the directing pins at D and and I: ; an elevation of the mesh frame at ; the vibrat ing frame which communicates the rotatory motion to the mesh frame at G ; the two directing pullics at lif I ; one treddle at I.
Figures 8, 9, 10. I 1, 12, are intended to show more clearly the adaptation of certain parts which are imper fectly represented, or omitted in the general figure.
Fig. 8. exhibits -a barrel by which the rotatory motion may very conveniently be given to the mesh frame. Two cords may be attached to the wheel at B, and passing round it in opposite directions, will move the vibrating frame. From the smaller part of this barrel or cylinder at A, two similar cords will complete tne connection with the treddlcs 1 and 2. Thus the depression of the treddle 1 will produce one motion, and that of the treddlc 2 will in like manner give the inverted one. Fig. 9. is a profile of the same apparatus. Figures 10. and 11. ex hibit two different ways of giving motion to the cross rails and pins for changing the mesh. In Fig. 10. this is done by a band passing over a pulley. In Fig. 11. the same is done by two inverted racks, and an intermediate pinion. The first of these will be the cheapest plan of construction, but the second is by much the most steady and certain in its operation. Fig. 12. is a plan for shift ing the receiving beam tq wind up the finished net. It is done merely by pulling a handle at A, a weight (not represented) being suspended from the other extremity B of the cord.