What is, the additional expense of a patent for the colonies ?The expense for the colonies is about £5 additional. Have you ever been engaged in any law-suits for the maintenance of parents-Never.

Do you know the grounds upon which they are usually set aside? I have hardly ever been in court when they have been tried, but I have heard the reasons; they are generally for want of novelty, or else a bad title.

MISCELLANEOUS.

PULMONARY CONSUMPTION.-The "Globe" states that a student of medicine twenty-six years of age, attacked by a malady which one of the commissioners appointed by the Académic des Sciences recognised to be pulmonary consumption, had been completely cured by the administration of chlore.

VOLCANO. A short time ago, a species of volcanic mountain was discovered in the environs of Sarrebruck, Prussia. It is in the form of rather an irregular cone, of six or eight hundred feet in height, and covered with wood, except towards the summit, where there is no vegetation but moss. The heat of the soil increases gradually towards the summit; from whence issues, through a small crater of thirty feet, such warm steam, that an egg may be boiled by it in a few minutes.

GREASE SPOTS.-The following method of removing grease and oil from silk and other articles, without injury to the colours, is given in the "Journal des Connaissances Usuelles :"-Take the yolk of an egg and put a little of it on the spot, then place over it a piece of white linen, and wet it with boiling water: rub the linen with the hand, and repeat the process three or four times, at each time applying fresh boiling water; the linen is to be then removed, and the part thus treated is to be washed with clean cold water.

ON MIXTURES OF WHEAT FLOUR.-Several varietics of flour having been submitted to M. Henri, for examination, in order to discover the presence of potatoe flour. By means of a good lens, he found it easy to distinguish the brilliant crystals of the starch, but as that did not afford him the means of estimating the proportions of the mixture, he proceeded to ascertain the quantity of gluten yielded by these specimens of flour, taking, as a standard of comparison untouched flour, prepared under his own observation. Of twenty-five specimens of pure flour made from corn of 1827 and 1828, was obtained as a mean result, 101 per cent. of perfectly dry and pulveralent gluten, whilst the flour announced as mixed, gave only from 6 to o per cent. of perfectly dry gluteu. Hence it will be easy, by the simple operation of extracting the gluten, to prove whether flour be be mixed, and to what extent.

LANGUAGES IN AMERICA-11,647,000 persons speak English ; 10,584,000 Spanish, 7,593,000 Indian 3,740,000 Portuguese; 1,242,000 French; 219,000 Dutch, Danish, and Swedish.

PATENT IMPROVEMENTS IN BLOCK PRINTING.

By JOHN APPLEGARTH, of Crayford, Kent, 1829.

THE improvements for which this patent has been granted, are produced by an apparatus, which will facilitate the accurate arrangement of the square blocks employed in calico-printing when used successively for the continuation of agiven pattern. This apparatus is composed of two principal divisions, the first being of the nature of a table or stand, on which the calico, or other stuff required to be printed, is to be laid to receive the impression of the blocks, and the second consisting of a frame that fulfils the chief purpose of the object of the patent. The table, or stand, is made of horizontal stone slabs, a little exceeding the breadth of the stuff, and of the same length, being intended for printing handkerchiefs or shawls. These slabs are placed successively in one line, within about an inch of each other, on parallel brick walls, of between two and three feet in height, and over them a thick piece of blanket, or other proper woollen stuff, is laid, which is either nailed to pieces of wood fixed beneath the intervals between the stone slabs, or is kept down by metal rods placed across in the same intervals, and passed through staples secured to the walls at each of their ends. A frame is then prepared to lay over this table, containing as many square compartments as there are slabs, which is fastened at one side of the table to hinges, that project from each of the supporting walls for that purpose, which allows the frame either to lie horizontally in close contact with the slabs, or to be raised up vertically when the calico, or other stuff is being laid on the slabs, or removed from them. At one extremity of this table of slabs a row of tenter hooks is placed across, to which one end of the piece to be printed is fixed, and it is then laid evenly over the slabs, and fastened down in the intervals between them by the rods passed through the staples before mentioned, after its farther end is drawn tight by means of a cross bit of wood to which it is attached by a similar row of tenter hooks, that is either fastened to the other end of the table by cords, or is drawn towards that end by weights attached to the extremities of the same cords. Supposing the calico or other stuff to be arranged and fastened down evenly over the table of slabs, and the frame to be let down horizontally, in contact with its surface, a block is then to be taken, having a fourth of the area of one of the square compartments of the frame, ou which the pattern preferred has been cut, so that the joinings of the figure may fit accurately, on shifting its position; and the colour having been applied to its face, either by dipping it on the colour. sieve, or by colour rollers, it is then to be pressed down by a blow or other means, in one corner of the first square compartment of the frame, then in the next corner, and so on successively through the other remaining corners, care being taken to keep the proper angle, of the block next the corners of the compartiment; one handkerchief or shawl being thus stamped, the same process is to be repeated in all the other compartments of the frame, until the whole piece is completed. When a medallion, or other central figure, is to be inVOL. IV. No. 78. 1ST JANUARY, 1830.

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pressed on the middle of the handkerchief or shawl, then a moveable frame is to be formed of four pieces of wood, of the length of one of the compartmeuts, crossed so over each other (by dividing the joinings) as when laid in the compartment, to divide its area into nine equal squares; in the central square of these, a block, having the whole of the intended medallion, or other figure, eut on its face, is then to be stamped in the manner before described; or a block, having a quarter of the same figure cut on it (and, of course, only fourth of the area of the central square,) may be used, and the impression be made of the whole figure by four successive operations, in the same way as with the larger blocks in the process first recited. When only a border is to be stamped on a shawl or handkerchief, the patentee directs that a block of another shape be used, which is to be of the breadth of the intended border, and of such a length as to extend from one angle of the square compartment of the guiding frame to within a distance equal to its breadth, of the adjoining angle, and the pattern proper for the angle of the border, having been cut at the end of the block, placed in the first instance close to the angle of the square compartment; at the next transfer, that end of the block is to be laid in the space left at the extremity of the first impression, where it will form the second angle of the border; and the block being applied successively at the other sides of the compartment in the same manner, will, at the fourth impression, complete the border.

POOLE'S PATENT STEAM-BOAT PADDLES.

WE may congratulate our readers and the public that an apparatus has at length been not merely devised, but brought extensively into actual and beneficial operation, by which the inconvenience and waste of power, attending the use of the common paddle-wheel are completely obviated. Unlike the generality of its predecessors in this branch of mechanical invention, the combination of parts is of the utmost simplicity, and such as to introduce so very little additional friction, that it cannot fail of realizing those important advantages to steam navigation, which theory has long shown to be a desideratum in mechanics. The gentleman who has favored us with the annexed communication renders it unnecessary for us to say more in this place on the subject.

To the Editor of the Register of Arts.

SIR,-Numerous have been the descriptions given by you since the commencement of your very useful publication, of patented and other methods for an improved mode of propelling steam vessels through the water. Having paid very particular attention to whatever has appeared on that head, I think I may venture to say (notwithstanding many of the newly invented paddle wheels have been highly praised by some of our first mechanicians, as combining all which was necessary to effect the purpose required) that to this time, there are none that have answered the expectations entertained of

them; nor is there one in actual and beneficial practice; a sufficient proof of the entire failure up to this period. Still by the frequent dissertations you have given on the defects of the radial paddles, and the nature of the remedies to correct them, the mechanical mind of the country has been so directed to the consideration of the subject, that I doubt not the difficulties will ere long be solved, and a means of navigating by steam, without injury to the banks, be afforded to the principal rivers and canals of the kingdom.

The object of this communication is chiefly to introduce to your notice, and thereby to the public, another candidate for an improved paddle wheel, in a Mr. Poole, a smith of this town, who is possessed of considerable mechanical invention, and is also a superior operative, and to whom I have frequently made known whatever has been offered to the public on this subject, either in models, or attempts in practice. Mr, Poole has recently patented his invention, and I believe it will be found to surpass every other of the same kind, hitherto offered to the public. That you may be the better enabled to describe his new wheel, satisfactorily to your numerous readers, he herewith sends you his model, made on a scale of an inch to a foot; and of which you will find the following to be among its principal features. The wheel is a common one, to be suited to the size of the vessel it may be designed for, except that the float or paddle is not fixed to the radii, but vibrates on its axis in the rims of the wheel. On the side of the vessel, is placed, very securely, two concentric circles of iron, placed vertically edgeways, with a space of about one inch and a half between them, forming thereby, what may be called a rail-road, on the side of the vessel for a guide-pin, fixed on the end of a lever, attached to the paddle axle to travel in. The concentric circles before mentioned, are placed excentric to the axle of the wheel, and the paddles are thereby carried round, so as to enter and leave the water in such angles as to avoid the splash at entering and the lift at coming out. This wheel allows advantageously of a deeper immersion in the water, than the radial paddle, obtaining a greater power by being brought to a leverage on a denser medium than the surface water, and thereby adding most materially to the propelling power of the wheel: it is equally efficacious in its back stroke. It should seem however that one third of the diameter of the wheel, from present experience, is the best dip, and as this may allow of the lowering of the main axle, and probably the reducing of the wheel, in consequence of the greater extent of paddle surface, that can be employed, the paddle boxes may be considerably lowered. The angle formed by Mr. Poole's arrangement, we know has been obtained before by Mr. Steenstrup, Mr. Oldham, and others; but it has hitherto been the result of intricate trains of wheels, endless chains, &c. &c.; the expence of making which, the loss by friction, the liability to injury, and the difficulty of reparation in complex machinery, are very sufficient reasons why their inventions have not been carried into practice. The same beneficial angle, however, is got by Mr. Poole's excentric rail-road, and is obtained by a mere lever connecting the påddle axis and the rail-road, which is traversed as the wheel is