As to the smith work of the a great error was committed in making the under frame part that supported the whole machinery of too slender a bar of malleable iron, and which had to be formed into a cir cular ring the flat way ; for by the great number of heats that it received in the blacksmith's fire before he could bring it nearly to a circular form, he reduced it much in strength, and it was further reduced by filing and grinding before the blacksmith could make it in-. to a truly flat and circular ring ; and of necessity it had, after all, to be pierced with a number of holes for the pillars, &c. &c. so that when loaded with the weight of the machine, it vibrated much, even when travelling along a smooth even surface. A similar error was also committed in making the cutter circle of too thin mal leable iron, for which. reason the figures of these parts are here drawn to represent cast iron circles, as all the other circles of the machine were. With respect to the other parts of the machine, they acted up to expec tation.
The only uncut corn that was in the immediate neigh bourhood of the machine, was that of a small corner of coarse new broken up lea ground, sown for the first' time with oats, of about thirty yards in length.
The first trial of the machine was made in presence of several spectators, on the side of the plot that ap peared to have the evencst surface, when the machine cut and collected, in a very neat manner, the length of the plot, not leaving behind it a single uncollected straw, and laid down the cut corn into a regular con tinued swath, nearly at right angles to the line that the horse, travelled in. By the machine cutting in this manner thirty yards in length, was evidently shown the practicability of making a machine to cut a much greater extent, as also free from all the defects here mentioned.
The next trial of the machine was discouraging to those that could make no allowance for the slenderness of the bottom frame, which ought to have been thrice the strength that it was made of.
The piece of ground that the second trial was made on, was much more uneven than wc were aware of; for the unrottcn rushy sward was found to be nearly as the plough had left it, the horse having only moved forward fur a short way, when the roller wheels sunk into a deep unobserved hollow, and the exertions of the horse made the bottom part of the frame bend so much up, as caused the cutters to act against the cover plate with such force, that one of the cutters cut an inch and a quarter into it, another at the same time three-fourths of an inch, and a third nearly half an inch, which was a sufficient proof of the power of the machine, but, at the same time more than a sufficient proof of the weak ness of the bottom frame part.
Several private trials were afterwards made with the machine, but it is unnecessary to give any other report of them, than that the great defect in the strength of the bottom frame part was manifest in them all.
2, Mr. Gladstone's Improved Reaping Machine.
In our article on Agriculture, we have given a full description, accompanied by a drawing, of the first reaping machine, invented and constructed by Mr. Gladstone, an ingenious millwright at Castle Douglass. In putting that machine, however, to actual trial, Mr. Gladstone found, that as the teeth for gathering the corn were on the upper side of the cutter, they never could get quit of the cut corn. The machine cut a yard's length with great perfection, but the corn after this stuck in the teeth, so that the growing corn was shoved forward, and the cutter went over the top of it. Ile was therefore led to remedy this evil, by the con struction which we shall proceed to describe.
This reaping machine is wrought by one horse, and is represented in Plate CCCCLXXIX. Fig. 13. is a from the side of the machine farthest from the growing corn. A represents the shafts for the horse like those of a common cart, B a diagonal piece of wood as shown at B in Fig. 19, for the purpose of strengthen ing the frame. G is the wheel carrying the one side of the machine, and giving motion to the gatherer, by means of a pinion working into a wheel fixed on the gatherer at H on Fig. 19, at M in Fig. 18. K is a block of wood or bolster for supporting the axle of the wheel G, and LLLL is the gatherer moving round the common cen tre N, and having the form of a cylinder of thin boards with teeth starting out lrom holes at the side where the corn is cut, and put back again within the cylinder as at Fig. 15. P is a small wheel carrying the principal part of the machine, with segments of cast-iron on it acting on the opinion on the socket of the cutter, as at Fig. Id. Q represents teeth cf wood for gathering up the straggled corn, and holding it for preparing it or the cutter, as at Fig. 19. Fig. 14. is a view of the cutter by itself, having a socket of cast-iron, with a pinion upon the socket about two inches in diameter, to take into the upright bar, Fig. 17, which is the centre bar, and is acted upon by the wheel P, whose motion is obtained from the surface of the ground and the weight of the machine.