tion of the road near the gate, with a section of the trunk underneath, and the mechanism employed for effecting the object. Supposing a two wheeled carriage, as a gig, to be driven towards the gate, the wheel on passing over the plate a, would cause the pin extending from the under side of the plate to press upon the arm b, of the weighted lever c, which would consequently raise the arm d. A rod e, is attached at one extremity by a swivel joint, to the end of the arm d, and at the other extremity by a crank to the wheel f. The depression of the arm b, will cause the arm d, to rise, and draw the rod e, which consequently turns the toothed wheelf, upon its axis. This toothed wheel takes into a pinion fixed on the lower part of the standard or axle g, of the gate, and as the toothed wheel turns the pinion is turned also, which throws the gate

open.

The weight of the carriage in passing over the plate a, having thus caused the gate to be thrown open, as shown in the figure; it is held in that situation by a catch in a post, similar to h, against which the back of the gate strikes when open.

The carriage having passed, the gate is made to close itself, by the wheel rolling over a plate, similar to z, but at the opposite extremity of the trunk, and not shewn in the figure. This plate hanging upon a hinge, is depressed by the weight of the carriage, and its lever y, acting exactly in the same way as the lever c, above described, causes the rod a, to be drawn, which pulls a crank w, similar to that shewn in the post h, and an upright rod connected to the crank by these means raises the catch v, and sets the gate at liberty.

The gate being released, the weight at the lower part of the lever c, by its gravity now descends, and the arm a, pushes the rod e, back again into its place of rest, and

also turns back the toothed wheel f, which causes the pinion to turn and to swing the gate into its former position crossing the road.

A catch is placed upon the gate post, for the purpose of locking or holding it fast when closed, the construction of which is similar to the lever catches in common, and rods are connected to the catch, and to levers, exactly in the same way as shewn at w, x, y, z, but placed on the other side of the road: by which means the wheel of a carriage in approaching the gate and passing over a lever plate in the track, releases the catch, before the apparatus comes into play which forces the gate open in the manner above described.

It is scarcely necessary to add that the levers, rods, and other appendages exhibited in the figure, are to be exactly alike on each side of the gate, and to be placed at similar distances from the gate; when, a carriage approaching the gate in either direction will first act upon the catch lever of the resting post, and unlock the gate, then by passing over the plate a, cause the gate to be thrown open in the way described, and afterwards acting upon the catch-lever of the back post, release the gate, and allow the weighted levers to close it again; when the catch of the meeting post immediately locks the gate fast.

[Inrolled November 1826.]

TO JOHN BELLINGHAM, of Norfolk-street, Strand, in the County of Middlesex, Civil Engineer, for his newly invented improvement, or improvements, in the construction of Cooking Apparatus.

[Sealed 18th April, 1826.]

THE improvements proposed by the patentee, the

particular novel features of which we are unable to define, have for their object, the construction of a cooking apparatus, consisting of boilers, ovens, hot-closets, &c. The fire place is situated about the middle of the erection, and from it emanate flues in different directions, which carry the smoke and heated vapour arising from the immediate combustion of the fuel, and bring it in contact with the external surfaces of the several vessels and chambers, for the purpose of heating them.

We cannot discover the slightest feature of novelty in the construction of this apparatus, unless it may be in the particular proportions, which one vessel bears to another, or in the particular positions and forms of the several vessels, none of which present any appearance of peculiar utility. We should therefore have been completely in the dark as to the invention of the patentee, had he not stated that his claims consist in forming a certain projecting part of the boiler square, and causing it to extend partly over the fire; and in making the hot plate upon which stew pans and other articles are to be placed, in several pieces, joined together by rebate edges, by which contrivance the expansions and contractions of the metal, caused by heat and cold, will not be likely to crack the metal, as is frequently the case, when the hot plate is made in one piece.

[Inrolled June, 1826.]

Original Communications.

THE improved process of concentrating and crystallizing sugar in vacum by steam, as conducted upon the plan of Mr. Howard, having become a subject of very considerable interest and inquiry, we have thought it desirable to present our readers with a description of the apparatus and mode of proceeding, as practised by those houses in London, whom the inventor has licensed to work under his patent.

Mr. Howard first introduced his plan under a patent granted 31st October, 1812, "for a process for preparing and refining sugar;" and subsequently improved that process under another patent, dated 20th November, 1813. We shall therefore first state what were the objects proposed in the specifications of these patents, and afterwards describe the apparatus at present in use.

With respect to the first specification, the patentee commences by observing, "From the known fact that water dissolves the most uncrystallizable sugar, in preference to that which is most crystallizable: and also upon a discovery I have made, that no solution of sugar in water can, (unless already highly concentrated) without material injury to its colour, and crystallizing power, or to both, be exposed to its boiling temperature during the period required to evaporate such solution to the crystallizing point, I have estabished and adopted the following operations:

In the first instance I do submit raw or Muscovado sugar to a primary operation, by well mixing as expedi

tiously as possible, the said sugar with such a quantity of water, as will at the common temperature of the atmosphere bring it to a magma of the consistency of well worked mortar and 1 do leave the same at rest for the space of an hour or more, and then heat it to a moderate temperature, say from 190 to 200 Fahr., which may be most conveniently affected in a vessel surrounded by boiling water, or steam, under the common pressure of the atmosphere, which apparatus is so well known under the name of the water bath, that it requires no particular description.

Having brought the said mixture of sugar and water to a uniform temperature, I then regulate its consistency if necessary, by the addition of more sugar, or a thinner magma, as may be requisite, in order to put the mass into such a state of semi-fluidity that it shall close behind the stirrer. I then fill the moulds with the mixture, imme diately from the bath, by any convenient means, and after suffering it to become cold in the moulds, as is usual when sugar has been boiled in the common method, I then take the stoppers out of the moulds, and suffer the molasses to drain therefrom, and as soon as the drainage has taken place, or somewhat sooner, I pare down the larger or upper surface of the lump, or loaf, or mass of sugar remaining in the mould, with any convenient instrument, until I find the sugar presents a uniform appearance.'

The sugar thus pared off from the lumps, is to be again mixed with cold water, and brought to a semi-fluid state as before, and in that state, is to be placed in the moulds upon the masses from whence it has been pared, and when this magma has become moderately dry, a cold saturated solution of fine sugar in cold water is poured upon it, taking care to place an intervening guard between. Or instead of the solution of fine sugar, the magna may be