Mill, a machine for grinding corn, etc. of which there are various kinds, according to the different methods of applying the moving power ; such as water-mills, those worked by horses, wind-mills, etc.

Without discussing the mechanical construction of this valuable contrivance, we shall, conformably to our plan, omit the less interesting patents granted for inventions or improvements, and present to our readers an account of Mr. Thomas Rustall's parish, or family-mill and bolter : for which the Society for the Encouragement of Arts, etc. in 1800 voted him a premium of forty guineas.

Description of the Plate representing Mr. RUStall's FamilyMill and Bolter.

Fig. 1. A, the handle of the mill.

B, one of the mill-stones, which is about 30 inches in diameter, and 5 inches in thickness, moving with its axis C.

D, is the other mill-stone, which, when in use, is stationary; but which may be placed nearer to, or at a distance from, the moveable stone B, by means of three screws passing through the wooden block E, that supports one end of the axis C; after it has be en put through a hole or perforation in the bed-stone. The grain likewise passes through this perforation from the hopper F, into the mill.

F represents the hopper, which is agitated by two iron pins on the axis C, that alternately raise the vessel containing the grain, which again sinks by its own weight. In consequence of this motion, the corn is conveyed through a spout, that passes from such hopper into the centre of the mill hehind, and through the bed-stone D.

G, a paddle, regulating the quantity of corn to be delivered to the mill; and, by raising or lowering which, a larger or smaller proportion of grain may be furnished.

H, the receptacle for the flour, into which it falls from the millstones, when ground.

I, represents one of the two wooden supporters on which the bed-stone D, rests. These are screwed to the block E, and likewise morticed into the lower frame-work of the mill at K, which is connected by means of the pins or wedges L, L, L, that admit the whole mill to be easily taken to-pieces.

M, a fly-wheel, placed at the farthest extremity of the axis C, and on which another handle may be occasionally fixed.

N, a small rail, serving to keep the hopper in its place; the farthest part of such hopper resting on a. small pin, which admits of sufficient motion for that vessel, to shake forward the corn.

O, a spur-rail, for strengthening the frame-work of the mill.

P, the front upright, that is morticed into the frame-work, and serves as a rest for the end of the iron axis C, which is next to the handle. — On each extremity of such axis, there is a shoulder, which keeps it steady in its place.

Lastly, there is a cloth - hood fixed to a broad wooden hoop, and which is placed over the stones while working, to prevent the finer particles of flour from escaping.

Such is the outline of Mr. Rust-all's useful mill; but, as a bolter, or sifter,becomes necessary for separating the flour from the bran, he has contrived a machine upon a simple and excellent construction, of which the reader will find a delineation in the same plate.

Fig. 2, represents this bolter, with its front removed, in order to display its interior structure; the machine being three feet ten inches in length, 19 1/2 inches in breadth, and 18 inches in depth.

A, is a moveable partition, sliding about four feet backwards or forwards, from the centre of the box, upon two wooden ribs, which are are fixed to the back and front of the box, and one of which is delineated at the letter B.

C, the lid of the bolter represented open.

D, a slider, which is moveable in a groove made in the lid, by means of two handles on the back of such lid.

E, a forked iron, fixed in the slider D ; and which, when the lid is shut, takes hold of the edge of the sieve F, and moves it backwards and forwards on the wooden ribs B, according to the agitation of the slider.

G, represents a fixed partition in the lower centre of the box, which it divides into two parts, in order to separate the fine from the coarse flour : from this partition, the slider A, moves each way about four inches, and thus affords room for working the sieve.

H, a board that is parallel to the bottom of the bolter, and forms part of the slider A. This board serves to prevent any of the sifted matter from falling into the other partition.

I, represents two of the back feet which support the bolter.

Fig. 3, of the plate above mentioned, is a view of the top, or upper part of the lid of the boiler.

K, the slider that moves the lengthwise of the bolter.

L, L, the bandies by which the slider is worked.

M, a screw, serving to hold the fork, which imparls motion to the sieve.

Fig. 4, represents the forked iron, E, separately from the lid.

Mr. Rustall's inventions are equally ingenious and economical: they bid fair to be of very general utility ; as both the mill and bolter may be constructed at a moderate expence, and occupy only a small space of ground. The former may even be worked in a public kitchen, or within a room in a farmhouse, without occasioning any great incumbrance.

The particular excellence of the mill consists in this circumstance, that, from the vertical position of its stones, it may be put in action without the intervention of cogs or wheels. It may be employed in the grinding of malt, the bruising of oats for horses, and for making flour, or for all these purposes : it may likewise be easily altered, so as to grind either of those articles to a greater or less degree of fineness.

Another advantage peculiar to Mr. Rustall's contrivance is, that one man is sufficient to work it; though, if two persons, namely, a man and a boy, be employed, they will be able to produce, in the course of two hours, a quantity of flour sufficient to serve a family, consisting of six or eight persons for a whole week:—repeated satis-factory trials have proved, that this mill grinds the corn completely, and at the rate of one bushel of wheat within the hour.—Besides, the industrious farmer will thus be enabled to make comparative experiments, on the quality of his grain, and may furnish himself, at a trifling expence, with flour from his own wheat; without apprehending any adulteration; or without being exposed to the impositions, or caprice, of fraudulent and avaricious millers'.

Lastly, though Mr. R.'s bolter be more particularly calculated for sifting flour, it may also be applied to various other useful purposes, and especially with a view to obviate theinconveniencies necessarily attendant on the levigation of noxious substances, and to prevent the waste of their finer particles,

The original mill may be inspected in the Repository of the Society for the Encouragement of Arts, etc. Adelphi; and we understand from Mr. Taylor, the Secretary to this patriotic association, that the inventor of the machinery, Mr. THO, Rustall, wheelwright, of Pur-brook-heath, near Portsmouth, engages to furnish the whole apparatus, and to deliver it tree of carriage, in London, for the moderate price of twenty guineas.

Mill. - In September, 1801, a patent was granted to Mr. Zacha-RIah Barratt, for a portable mill, designed to grind corn ; and which may be worked either by wind, water, or horses. This contrivance differs from the common mills, chiefly in the following particulars : 1. That its size may be enlarged, or reduced according to circumstances ; the whole running on castors; 2. The mill-shaft is moved by a crown wheel, containing three notched orbits, each being at some distance within the other; and which wheel may, by a slight alteration, be constructed so as to be set in motion, either by sails, by horses, or by water; and lastly, the machine may, if required, be conveniently erected at the gable end of a barn. - A more particular account of this mechanical invention is given in the i6th volume of the " Repertory of Arts" etc. where the apparatus is illustrated with an engraving.

Another patent was lately granted to Mr. Thomas Wright, for a Hand Stone Corn Mill. The frame of the machine is three feet square, and three and a half feet in height: the stones are 18 inches in diameter, and are inclosed in a tub, supported by two cross-bearers. Beneath these stones, there