Mr. Huddart took out in 1805 a fourth patent for a system of machinery, which. " though not new when taken separately, tends to lay cables in a manner that is to all essential and substantial purposes new." This machine is composed of three strand frames, which revolve round a common axis. Fixed to that axis, and revolving with it, is a top, along whose grooN es the strands pass to their point of union, where they are formed into a rope, which is drawn away, when made, by grooved wheels. This machine seems to combine some of the parts of Cartwright's Cordelier, and of Fothergill and Grimshaw's Machines.
In 1806 Mr. Curr of Sheffield secured, by a patent, " a method of spinning hemp for making ropes or cordage." In order to regulate the number of twists in the yarn to the distance moved through by the spin ner, lie connects a barrel with the spinning wheel, and therefore with the whirls which twist the yarn. The speed and motion of the spinner (with whom the rest keep pace) is regulated by means of the rope attached to his body unwinding itself from the barrel above mentioned. The great object of Mr. Curr's method is to produce an equal elongation of the yarns when the twist is taken out of them by the opposite twist of the strand.
This patent was immediately followed by another by the same patentee, "for a method of laying or twisting the yarns, by which they have a better and more equal bearing than they have in the common way." In the specification of this patent, Mr. Curr describes a me thod of regulating the motion of the top, and also of giving a regular motion to a perforated implement; which is a substitute for Mr. Balfour's top minor.
In the year 1806 Mr. R. 'Walker took out a patent for an "improved method of making ropes of every dimension by not only making all the yarns bear equally in the strand, and laying the strands uniformly in the rope, but also by making the rope or cordage from the yarns in the same operation." In this ma chine the rope is twisted by the same frame which twists the strands ; and the principal difference be tween this and several other patent machines is, that Mr. Walker has each yarn wound on its own bobbin, and arranged in different tiers round an open cylinder, and made to pass in a concentrated state through a hollow axis at one end of the cylinder, where it is re ceived on a pulley fastened to a frame that twists the strands into a rope, and on which the strand frames revolve separately in twisting the strands. Each
strand passes from these pulleys over another pulley near the centre of the machinery, to a grooved block which revolves with the main frame, on which the strand frames turn round separately. At the place to which the strands converge above this block they are formed into a rope, which is hauled away as it is made, and wound up by machinery. Mr. Chapman remarks that the final effect of this machine is to make a rope on Mr. Balfour's principle. Mr. Walker also describes a plan of making a strand separately, but we must refer the reader to his specification in the Repertory of .grts, No. 70, 2d series.
In 1807 Mr. Sycds took out a patent for improve ments in ropemaking, but it does not seem to contain any thing practically different from the plan already described, though the combinations of the machinery are different.
In 1807 Messrs. W. and E. W. Chapman took out a patent for a method of making a belt or flat band of two or any greater number of strands of shroud-laid rope placed side by side, so as to form a band of any determinate breadth. These strands, according to Mr. Chapman, should in general be alternately twisted the contrary way to each other, and the yarns the opposite way to the strands. The advantage of this invention consists in this, " that the loss of strength by the com bination of these strands into a shroud-laid rope is so considerable that, exclusive of the reduction of length from being twisted into a rope, which is about one sixth the strength of two strands, made in such a way as to make all the yarns bear an equal tension, or nearly so, will, when laid side by side, be nearly equal to three such strands when combined as a rope." Mr. Chapman has also invented a " trunk or frame with its appara tus, for combining speedily and correctly together any requisite number of strands or other flexible substan ces laid side by side." Mr. Chapman is of opinion, that these belts are stronger than salvages composed of the same number of yarns placed side by side, which Duhamel and others considered to be the strongest combination of yarns.