D, D, the feeder in the old patent, and sheet iron pan and feeder, in the improvements.

6

Description of a machine for scattering manure upon land, by means of a Manuring Wagon,' patented by JAMES BOWMAN, Beaufort, South Carolina, August 12th, 1829.

EVERY agriculturist is aware of the immense labour attending this process, as it is ordinarily performed; a labour so great as frequently to prevent its being undertaken, notwithstanding the manure may be at command. The scattering, when done by hand, is generally very irregular, the consequences of which are plainly to be seen in the unequal growth of the crop, as vegetation advances. These difficulties have been completely obviated by the invention of Mr. Bowman, who has satisfactorily tested the value of his machine, before applying for a patent; the facility, rapidity, and perfection with which it acts, not only excited the admiration of a number of intelligent planters in his immediate neighbourhood, who witnessed it, but far exceeded his own expectations. The plan was undertaken without the most remote idea of obtaining a patent, which was suggested only by the excellence of the instrument itself.

The accompanying engravings will afford a very correct idea of the construction of the wagon, and the apparatus for scattering the manure. Fig. 1, gives a bird's eye view of the body of the wagon, which is of the size commonly used for agricultural purposes. Its sides are inclined planes, meeting the bottom at an obtuse angle. In the bottom, near the hinder axle, there is an opening made, as seen at A, of about two feet in length, and eighteen inches in width.

Through this opening the manure is to pass, as it is scattered by the machinery seen in Fig. 2, which represents the hinder part of the frame of the wagon to which it is attached.

B is a revolving shaft, usually made square, and which crosses the bed of the wagon at a short distance from the axle. This shaft carries ten pins, made of. iron, or of any other suitable material, and extending out a sufficient length to occupy the aperture left in the bottom of the wagon, but without touching its sides or edges. These are seen at C, and also in the opening at Fig. 1.

Upon the end of the shaft, there is a cog-wheel, D,

Fig. 2.

which is turned by a similar, but larger wheel, E, fixed on the hub of one of the hind wheels; and, of course, when the wagon is drawn forward, the shaft will revolve, and the manure be scattered. Mortise holes are represented upon the frame, on each side of the shafts; these are to receive wedges, by means of which the shaft may be thrown in or out of gear. An ordinary hand can drive the wagon, and shovel the manure towards the opening, and in this way perform the labour of several strong and able men.

FRANKLIN INSTITUTE.

Monthly Meeting.

A Stated Monthly Meeting of the Institute was held at their Hall, September 24, 1829.

Mr. S. J. ROBBINS was called to the chair, and WILLIAM HAMILTON was appointed Secretary, pro

tem.

The minutes of the last meeting were read and approved.

The following donations were made to the library and cabinet of minerals, viz. Nicholson's Practical Builder, in seventeen parts; and Nicholson's New Carpenter's Guide; presented by Mr. J. G. Yatman. Bigelow's Elements of Technology; presented by Hilliard, Gray & Co. Two Addresses, delivered before the American Institute, July 4, 1828, and July 4, 1829. Three Reports of Committees to the American Institute; presented by the American Institute of New York. Instructions, Théorique et Pratique Sur les Brevets D'Invention. Exposition D'un Nouveau Systeme de Perspective, presented by J.G. V. De Moléon. Several Specimens of Minerals from Massachusetts; presented by W. R. Johnson.

The Corresponding Secretary also presented the following Mechanical and Scientific Journals, received in exchange for the Journal of the Institute:-London Journal of Arts and Sciences for August, 1829; London Register of Arts, and Journal of Patent Inventions, for August, 1829; Gill's Technological and Microscopic Repository for August, 1829; Annales des Mines, Vol. 4, No. 6, and Vol. 5, No. 1; Annales de Chimie et de Physique for March and April, 1829; Bulletin de la Société D'Encouragement pour L'Industrie Nationale, for March and April, 1829; Journal des Connoissance Usuelles et Pratiques for June, 1829; Recuiil Industriel, Manufacturier, Agricole et Commercial, for April, 1829; Bibliothéque Physico-économique for June, 1821.

The Committee on Inventions presented reports on the following inventions and improvements submitted to them for examination, by the inventors, viz. On a Compound Protractor, by Ennion Williams, of Philadelphia. On a Combined and Rotary Protractor. On a machine for ascertaining and marking, in a profile form, the Soundings of Coasts, Bays and Harbours, by Ebenezer Cooley, M. D. On an improved Rail-road Car, by Mr. James Wright, of Columbia, Pennsylvania. On an improvement in Locomotive Engines, by W. R. Hopkins, of Albany, New York.

The Corresponding Secretary, Dr. Hays, communicated to the meeting letters from J. G. V. De Moléon, Chief Engineer of the Domains of France; from the Franklin Institute of Rochester, New York; from the Maclurian Lyceum of Science of Philadelphia; and two from the American Institute of New York.

W. R. Johnson submitted for examination two modifications of apparatus for igniting spongy platina, by hydrogen gas, on which apparatus some observations were offered.

The following queries were submitted for discussion, which were read, and laid on the table, viz.

1st. What is the best construction of Barker's mill, and what its maximum effect?

2nd. What is the true mode of computing the power of high pressure steam engines?

Sd. What is the proper height of a carriage wheel, with an axis of a given diameter, in order to be most efficacious in aiding the draught of horses in transportation?

4th. What is the absolute centrifugal force of a body revolving in a circle of a given diameter d, with a given velocity v?

5th. What is the rationale of the action of hydrogen gas on spongy platina, as discovered by Doëbereiner?

6th. Which will move down an inclined plane with the greatest velocity, a wheel of two, or one of four feet in diameter, supposing their weights the same, and the matter of each to be all disposed around in its periphery?

(Extract from the Minutes.)

W. HAMILTON, Secretary, pro tem.

S. J. ROBBINS, Chairman.

TO THE FRANKLIN INSTITUTE.

The following is submitted as an answer to some of the questions formerly proposed for discussion.

August 17th, 1829.

Very respectfully,

CHARLES POTTS.

Quest. What shaped aperture will deliver the greatest quantity of water in a given time and under a given head?

The obvious extent and importance of this question, has called forward many of the most celebrated philosophers and mathematicians to its investigation. Numerous and diversified experiments have been instituted, from some of which I shall endeavour to select such practical results as have been obtained, and which seem most likely to answer to the conditions of the question.

In the discharge of water through simple apertures, either in the sides or bottom of a reservoir, it is evident that with respect to the resistance which tends to diminish the full or natural discharge, we can have very little doubt whether the shape of the aperture ought, in order to present the least rubbing surface, to be square, triangular, or otherwise, since we know that of all equal areas, the circle has the least peremiter or circumference. Hence, if we suppose the water to be discharged through an orifice made in a thin plate, that discharge will be the greatest when the aperture has a circular form. The experiments of Bossut confirm this conclusion in a very satisfactory manner.

This might be submitted as a full answer to the question, were we to limit it to the phraseology of its expression: but as I conceive not only apertures, but also such contrivances as are denominated adju tages, from their property of promoting the discharge of water, to be implied in the question, I shall extend the inquiry on this construction. Newton first noticed that running water delivered through apertures did not preserve an equal section, but that the column after leaving the aperture gradually decreased in thickness for a distance about equal to the diameter of the orifice, after which it increased. This contraction of the effluent stream, which is evidently owing to the filaments of water in the reservoir being drawn towards the aperture by forces acting in different directions, is what demands particular attention, inasmuch as the proper shape of the adjutage called for in the proposition is found to depend upon it.

One of the primary objects in the experimental researches of Bossut and Michellotti, was to determine the different effects of this contraction under different circumstances. Michellotti, after carefully examining the form which the water naturally assumed in its effluent state, determined the figure or shape of that part of the natural jet between the vena contracta and the reservoir, to be that formed by the revolution of the trochoid (cycloid) around the axis of the jet, with dimensions having the following ratio.

Diameter of the outer orifice (vena contracta)

Do.

inner

Length of the axis

= 36.

= 46.

= 96.

The effect of this adjutage was such as to give a discharge of 983 when the natural discharge would have been 1000.

According to the results deduced by Eytelwein, a conical tube approaching to the figure of the contracted vein produced a discharge equal to .98 of the full velocity, which agrees in a striking manner with the preceding.

With the view of showing more fully the effect of short tubes on the discharge of water, and also of drawing a comparison with the above mentioned adjutage, I shall quote the results of several experiments instituted by professor Venturi on this head. These experiments are considered highly important in practical hydraulics.

The same quantity of water, 4.845 English cubic feet, flowed out of the same vessel, which was kept constantly full, through the following adjutages, in the time annexed, which is expressed in seconds. The altitude of the water above the centre of the aperture of the adjutage was always equal to 34.642 English inches.

Through a simple circular aperture, Fig. 1, in

Fig. 1.