GROUNSELL'S IMPROVED CORN AND

MANURE DRILLING MACHINE. [Patent dated 12th June; Specification inrolled 12th Dec., 1839.]

Figure 1, front page, is a side view of part of an ordinary drilling machine, having the improvements applied thereto. The object of the improvements is to drill corn, grain, pulse, and manure, at intervals, and not in a continuous stream; the intervals or distances apart of such drilling can be varied at pleasure. The first part of the invention relates to the application of valves, and apparatus to work them at intervals. On one of the wheels of the drilling machine (of which zz is a part) is attached the circular ring a, in order to carry a series of studs bb; and according to the distance such studs are set apart, so will be the closer or wider sowing or drilling of corn, grain, pulse, and manure.

If the

several holes formed in the ring a, be tapped with suitable female screws, and the end of each stud b be screwed, the studs may be set closer or farther apart, according to the desire of the person nploying the machine. c is an axis

turning in suitable bearings in front of the machine; d is a projecting arm affixed to the axis c; on the lower end of the arm da curved prolongation is hinged in such manner, that it may be lifted upwards, and will not be so acted on by the studs b, as to move the valves in the event of backing the machine; but when the machine is drawn forwards, each stud will strike against the projection d, and by this means cause the axis c to move partly round, and in doing so to open the valve or slide, and let out the grain and manure in the following manner :e is one of a number of arms according to the number of drills affixed to the axis c, as is shown in the figure; each arm has a chain ƒ affixed thereto; these chains ƒ are also attached to the hooks g; h is another axis below the machine which moves in bearings h'; to this axis is affixed arms, one of which is shown at i. The number of such arms will depend on the number of the drills used in the same machine. These levers or arms i are supported at their outer ends by chains i', by which the depth of the lower end of the drill is permitted to enter the ground will be regulated. The

stems of the hooks g are attached by pin joints to the arms i, and to the stems g are attached the connecting rods j, which connecting rods each embrace its respective drill, and they are attached to the levers k, which at their lower end carry the valves or slides which close the drill; the levers k each move on a fulcrum at 7 affixed to the arms i. When the studs b act on the lower end of the projection of the arm d, the valves or slides will be opened, and allow of the seed and manure to pass, and again close, till the next stud b strikes the arm d. The closing of the valves or slides is assisted by the weights 'on the upper parts of the levers k. AA represents the coulter pipes; they are carried by the arms or levers i, and are of the ordinary construction.

It will be seen that the machine is arranged for drilling manure at the same time as the seed, the seed being supplied in the usual manner through the funnels and tubes mm, and the manure through the funnels and tubes nn, which are as usual suspended on chains to allow of considerable play. Variations may be made in the details, by which the slides and valves are acted on, in order to open and close them so as to sow at intervals, the valves or slides being suitably arranged to close the drill when shut, and allow of the grain, corn, pulse, and manure passing freely, when open.

Fig. 2.

The second part of the invention relates to the mode of supplying the manure to the tins.

In the ordinary construction for drilling manure, the projecting arms o o fig. 2 on the shaft p are spoons or hollow ladles, which, in the revolution of the axis p, take up a quantity of the manure, and effected without increasing the quantity of the area of floats immersed.

Sir. As one who has devoted much time and attention to making experiments upon various propellers, with a view to the improvement of the means of carrying on navigation by steam, I trust I may be allowed to offer the following observations upon the article, "Comparative experiments on propellers of different kinds," inserted in the last number (No. 854) of your very valuable periodical. My object in making these observations is to show that, however the results, as given in the communication, may warrant the conclusions drawn from them, these results have been obtained under such conditions of experiment as to render the conclusions of no value whatever, in the way of comparison of the useful effects of the different propellers with which the experiments were made. I hope that in offering my reasons for my difference in opinion from the author of the article in question, I shall stand excused from any desire to set up my views in absolute opposition to those of one with so high a name as Rennie; but rather, that my motive will be considered to be, a desire to show that in the ardour of experimenting, circumstances may be sometimes disregarded, which more coolly weighed, would be deemed altogether destructive of confidence in conclusions deduced from the results of experiments.

I may, perhaps, begin by stating that trapezium-shaped floats are no novelty to me, having experimented with them five or six years ago, and since discarded them, from a perfect conviction that

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when they were tried under equal conditions with rectangular floats, they were less efficient.

The first table, in the article in your last number, consists of the results of two sets of experiments with the different floats, immersed in two different degrees. From the table above, it is not easy to imagine the measures of the floats, though, from the conclusions drawn from the results, these may pretty well be defined, as well as the manner of placing the floats upon the two wheels. From the conclusions we learn, that the area of the trapezium float was half that of the rectangular float, while the trapezium float was one-third of the breadth of the rectangular float. Now, if the acute and obtuse angles of the trapezium floats were placed at the same distance from the centre of the wheel, as the inner and outer edges of the rectangular floats were, it is not easy to conceive that a trapezium, formed within the space occupied by a rectangular figure, and of half the area, and revolving in the same circle of action, could receive a resistance equal to that given in the table. We are, therefore, driven to conclude that, while the inner edges of the rectangular floats, and one of the angles of the trapezium floats, were placed at the same distance from the centre of the wheel, the other angle of the trapezium float, from the greater radius of this float, projected far beyond the outer edges of the rectangular floats, and, as a consequence, operated through a larger circle of action, in the same manner as would the rectangular floats of a larger wheel; and thus, the trapezium floats were resisted by the water, through an arc of a larger circle. Indeed, we are warranted in assuming thus much, by the third table of experiments, in which the greater comparative resisting action of the trapezium floats, is obtained by this manner of placing the floats upon the wheels.

There appears to be some mistake in stating the area of floats immersed in the first table; for we find, upon examination, that while the resistance of the rectangular floats is doubled, the area of floats immersed remains precisely the same, and this remark may apply, in a mitigated degree, also to the trapezium floats. I have much difficulty in imagining, how the immersion of the floats of a wheel, to double the extent, can be

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