Description of a Loom for making Fishing-nets; invented by Mr. JOHN ROBERTSON, of St. Mary's Wind, Edinburgh. With a Plate, From the TRANSACTIONS of the SOCIETY of ARTS, MANUFACTURES, and COMMERCE. A Premium of Twenty Guineas was voted by the Society to Mr. ROBERTSON for this Invention. A MACHINE for weaving nets has long been a desi deratum in the arts. Fishermen experience many difficulties from their nets being frequently broken by dogfish, and other marine animals, and the consequent length of time, required by the present mode of netting, in repairing their injured nets, or in making others. A fisherman is sometimes compelled, from such accidents, to relinquish fishing for a whole season. Any method, therefore, which leads to accelerate the fabrication of nets, without increasing the expense of them, must be beneficial to the community. From this consideration, I-have paid great attention to the subject, and now submit to the Society a model of ą machine which, it is presumed, will answer the purpose held in view, of expediting net-work, while, so far from increasing the expense of them, it will diminish it. I have, indeed, to regret, that from my obligation tą provide, by my own manual labour, for a numerous family, I have been unable to establish the utility of the invention, by experience on an extensive scale, I am, nevertheless, convinced, that the invention is better adapted for the object in question, than any which has hitherto been proposed. Reference Reference to the Engraving of Mr. ROBERTSON'S Loom for weaving Fishing-nets. Fig. 1 (Plate XVIII.) is the machine in a state ready to begin working, supported in a wooden frame. A is a beam, on which the twines for the net are rolled, in number equal to the knots tied, and from which they pass through circular tubes fixed in a bar B (shewn by dotted lines through the pulley, but seen better Fig. 2) which is fixed near the circumference of two equal pullies C, C; that turn on their axis by means of a cross-treadle, with small pullies at each end D, D, through which passes a band, one end of which is fastened on the frame at E, and the other on the pully C. At F, the band through the other pulley has one end fastened on the frame at G, and being wound round the farthest pulley C, is fastened on the under side of it, which by the alternate action of the treaddle on its axis H, moves the pullies C, C, and circular tubes from their situation in Fig. 1, to that in Fig. 3, and back again. In the centre of the pullies C, C, is fixed another bar P with a dove-tail groove, where the pirns that contain the twine are supported, (it being ne cessary to have two threads for every mesh, also one pirn more than there are tubes). In a groove under the dovetail is a slider L, moved by a wire K, fixed in each end of it, having pins in it, by which it moves the pirns backwards or forwards over the notches in the bar I so as to cast a part of the knot: the pullies C, C, and bar B, move round the bar I as an axis, but independent of it, the bar I being fastened through the pullies to the frame. M is a moveable bar (centred within two supporters N, N, having two joints) with hooks, both for catching the twine at the end of the circular tubes, and Hhh 2 by by crossing the hooks to the other side of the points of the tubes, to give the twine a turn for forming the knot, and by raising the points of the hooks, the ends of the tubes enter between them, as shewn Fig. 4: and by the circular motion of the bar B, when the two pullies C C, are turning on their centres by the foot, on the end, No. 1, of the cross-treaddle, and until the knots so formed. are close to bar B, Fig. 3, (it is then what we call a running knot) a part of which falls into a notch cut below the level of the supporters of the pirns in the bar I, then slide the pirns over the notches that contain the twine, the knot is then cast, and then by the foot on the other end, No. 2, of the cross-treaddle, until the points of the tubes are returned to its former position, then remove the knot by disengaging the hooks and the tubes, then the knots are made tight as the wrought-part of the net is rolled on beam O, on one end of which there is a pulley P, with a band that communicates with the pulley, on the end of a short roller Q, in which are fixed four cross bits of wood that answer the purpose of treadles for the feet, by which it is drawn tight. R is another short roller communicating with the roller A, serving to give out the proper quantity of twine for the length of the meshes, or to hold it while the other roller tightens the knot. S is the seat. Fig. 2. is a plan of the machine, the moveable bar and treadles left out to prevent confusion. Fig. 3. is the situation of the running knot when the pirn goes through it. Fig. 5. is the tube in the same position, shewing the manner the knot is twisted round it; and having the pirn and slider L taken out of the bar I, the dotted lines shewing at what height they come together. In the |