41

numerator may be; for instance, if we take any numerator for the fraction we shall always find the same figures constantly recur, and 0232, &c. being the equivalent for, we shall always find 0232, &c. recur in every multiple of the same. But the equivalent for,

0294, &c. does not recur in the multiplication by the numerator.

From this we may draw the inference, that this rule only applies to those circulates where the circle commences with

the first figure, as 0232, &c., and fails when applied to those that commence with the second or any subsequent figure, as 0294, &c. or 01086, &c. The first are called pure, the second mixed circulates.

In the course of my investigations of this subject, I noticed the following curious methods of obtaining the same result, which are equally applicable to all pure circulates :—

Rule 1. Divide 999 ad infinitum by the given number.

Divide the quotient ad infinitum by the given number, and observe that there are the same number of figures in each quotient.

From the last remainder obtained by the first operation, subtract the next preceding one for the numerator.

Proceed the same by the second for the denominator. Thus :- 9999999 =2.8666 3410172=-82177.

3488372

The last remainder of the first operation, 23282479-23258479; the next preceding remainder = 24000.

The last remainder of the second operation, 27208226-27139426; the next preceding remainder 68800, and 24000 = 13.

68800

Rule 2. Take the first quotient for the numerator, and the second for the denominator, and by complex fractions we have 2866

= 2838 and 8217 7396

99009

2838

and the fraction 2900

7396 9000

25542000 73220400

=

90009

RECENT AMERICAN PATENTS.

(Selected from the Franklin Journal.) IMPROVEMENT IN THE THEODOLITE, Samuel Stone, Long Green, Maryland.The patentee states his improvement to be" in the art of measuring distances at one station with a theodolite, or any other instrument by which an angle can be made either perpendicularly or horizontally," &c. The patent, however, is taken for an improvement in the instrument, and not in the art of using it. He says, "the first improvement which I claim is the mechanical addition to the common theodolite, by extending the diameter of the horizontal limb for the purpose of forming a surface as well as a centre on which a circular rim or plate revolves, as already described; and also the application of the logarithmic calculations as applied to the circle, as already described. But I particularly claim the improvement of measuring distances by an angle at one point or station, using the pole or stave, with its graduations, for one side of the triangle.'

With respect to its construction and use, the inventor says:--

"This instrument embraces all the principles of a modern theodolite; besides which, it contains the following improvements:The first improvement is a circular revolving plate, sliding or resting upon the limb of the. instrument, the upper surface of which forms a plane with the upper surface of the limb; on which are delineated a set of mathematical numbers, which supply the place of a table of logarithms, and all other logarithmic tables.

"In the second place, this instrument is so constructed as to supersede the necessity and use of a chain in all cases. The distance of any visible object can be ascertained at one station, as far as the flag-staff can be distinctly seen through the telescope of the instrument, to the exactness of chains, links, and decimals.

"It also calculates the latitude and departure of every course run, and the base and perpendicular of all elevations. It further embraces all the fundamental rules of common arithmetic, viz. multiplication, division, single rule of three, interest, mensu

ration of superficies and solids, gauging, &c. Any question in plain trigonometry, rightangled or oblique, can be solved on the instrument correctly; including all questions that can be performed by logarithms or logarithmic tables. The whole without the use of figures or a mathematical calculation."

The instrument has received the approbation of the New York Institute, the managers of which have awarded their highest premium, a gold medal, to the inventor.

IMPROVEMENT IN THE COMMON FIREPLACE, Ira A. Bean and Elijah Shinner, Sandwich, New Hampshire.-A box is to be formed across the fire-place somewhat like a hollow iron back-log; below this box or furnace there is to be an air-chamber, and a plate is to rise vertically near its back edge, so as, with the chimney back, to form a flue for the escape of smoke. In the top plate of the box there are openings for cooking utensils; there is an opening also for admitting fuel, and tubes to let heated air into the room, which, however, will never produce this effect, as the draught will be the other way, The claim is to "the construction of the box in the hearth, and the arrangement and application of the same, with the flues, funnels, and false back, to common open fireplaces; the object of which is to save room and fuel, furnish a cheap and convenient apparatus for cooking, and at the same time avoid the impure air occasioned by close stoves, and the steam from cooking-stoves."

The whole of the above-named objects will not be attained by means of this contrivance; we do not think that there will be any special convenience in its use, and it certainly will not be economical when intended for heating in the place of a well-constructed close stove.

MACHINE FOR WASHING AND CHURNING, Charles Otis, Finksburg, Maryland. -I make a revolving cylinder or barrel, which is to turn upon gudgeons in the usual way, and having an opening through which the articles to be acted upon may be introduced, and secured by a close fitting door, or shutter. I cause this barrel, or cylinder, to revolve in a trough which serves to eatch any suds that may be allowed to escape, and which, in the churning of butter, may be filled with water, either warm or cold, according to the season of the year, and thus facilitate the operation. The parts thus far described I do not claim as constituting any part of my invention, the same having been repeatedly constructed by others; but what I do claim is the following appendage within the revolving cylinders :-I place flat wings, or buckets, on the inside of the periphery of the cylinder, extending along from end to

-45

end; of these there may be two, three, or more, made of flat boatds, the planes of which stand in the direction of radii to the cylinder. These boards may vary in width from two to six inches, more or less, according to the size of the machine, and I sometimes perforate them with holes, to increase the agitation of the fluid. They also serve to lift the clothes and suds in washing, or the cream in churning, more effectually than the pins which have sometimes been employed for that purpose. I confine my claim exclusively to the employment of the wings, or buckets, herein described.

IMPROVEMENT IN FIRE-PLACES FOR GRATES TO BURN ANTHRACITE, Joseph Snyder, Pennsylvania.-The greater part of this fire-place is proposed to be made of cast-iron; the bottom of it is formed of two parallel plates, two or three inches apart, and constituting a part of a circulating flue. This may stand upon feet, raising it a little from the ordinary hearth, and on it rests the back and jambs, the back also being formed of double plates, connecting with those at the bottom. The grate is situated as is usual in open fire-places, and above it are double topplates also forming a flue between them. Hollow columns at the corner of this fireplace, in front, connect the hollow hearth with this hollow top, the back end of which passes into the chimney, in the manner of a Franklin stove; there is a damper situated on the lower plate of the upper base, which being opened allows of a direct draught into the chimney, but when closed, causes it to circulate around the whole structure. grate is lined in the usual way, and supposing the damper to be closed, the draught is over the sloping back into the back flue, then downwards between the two back plates, then forward in the hollow hearth, and upward through the columns into the cap flue, and back into the chimney. The claim is to "the principle of diffusing the heat of an open fire-place or grate to the hearth and parts situated below the fire, by a descending and ascending flue, or flues, and double hearth, as set forth and described."

The

THRASHING MACHINE, Thomas Rucker, jun., of Murphreysborough, Tennessee, assignee of Pendleton Check, of the same county. In this machine there are two revolving cylinders, one placed over the other other; the upper one is furnished with knives or cutters, acting against an opposing fixed cutting edge, and these together operate in the manner of shears. The grained ends of the sheaves are fed to this cutting apparatus, and the pieces cut off fall between a thrashing cylinder and a concave, grooved from end to end, in the form of saw teeth, by which the

46

grain is thrashed out. The claim is to " the manner of separating the heads of wheat or other grain from the straw, previous to thrashing it by the combination of machinery herein specified and described." It is said that in this instrument "the wheat is thrashed out more completely, and with far less labour than in those machines where the whole sheaf is operated on."

PUMPS AND FIRE-ENGINES, H. Gutes, Northampton, Massachusetts.-The body of this pump is to be a short cylinder or drum, its axis standing horizontally, and truncated or cut off on its upper side so as to reduce it to about two-thirds of its cylindrical capacity; this upper part is covered, watertight, by a horizontal plate. An axis passes through the cylinder, and has attached to it two buckets or leaves, standing at right angles to each other, fitting the lower part of the cylinder and the two heads, water-tight, to effect which they are made of durable metallic plates, screwed together with packing between them. Each of these leaves has a valve opening outwards, or towards the upper plate of the chamber.

The upper part of the drum is divided into two chambers by a fixed partition descending from the upper plate to the upper side of the vibrating axis, against which it is to fit water-tight. There are two valves opening upwards on the top plate, one on each side of the partition, and these are both covered by a conical delivery-pipe, by which the water is to be conducted as required. The receiving-pipe descends from the bottom of the chamber into the reservoir, or chamber.

The axis is to be made to vibrate about a quadrant of a circle, and those acquainted with hydraulics will see, that if the instrument be in good order, water will be raised by it. The construction of a pump, operating as described, is claimed. We could point to very similar plans of pumps, but we do not think it necessary to touch this point. Such pumps, if made with extreme care, will work promisingly at first, but they will soon go out of order. When in the best condition, we do not believe that such a pump is equal to the common piston and cylinder, the direction of the water being quite as much changed in it.

AN AUGER, William Jones, Portsmouth, Virginia. The specification of this invention is brevity itself exemplified; it consists of the following words :-" This improvement is a hollow auger made so as to embrace the bolts or fastenings in ships or vessels, and to cut the wood from around them, by which means the plank, &c., can be removed, without the delay, trouble, and expense, usually required by splitting them out,"

In the drawing, the auger is represented as twisted like the ordinary screw auger, but capable of allowing a bolt to pass within it. This must be a very useful thing, and, so far as we know, it is new.

MACHINE FOR CUTTING SAUSAGE MEAT, AND STUFFING SAUSAGES, Abraham and John Keagy, Pennsylvania.-The cutting is effected by means of a cylinder, around which are placed knives which we usually make of a triangular form, one of the sides being in contact with the eylinder. This revolves within a concave, or hollow cylinder, furnished with similar knives so placed as net to interfere with those on the cylinder. These knives are but placed somewhat obliquely, so as to stand in the direction of a spiral around the cylinders. The revolving cylinder has its axis placed horizontally in a box, the sides and ends of which are enclosed excepting where the meat is admitted and discharged. A gudgeon projects through the box at one end to receive a crank or wheel to turn the cylinder.

The opening for feeding is on the upper side, and at one end of this box; and this opening is surmounted by a vertical trunk, which may be in the form of a parallelogram, of the width of the lower box, and about half its depth, more or less. A piston, or follower, is adapted to this feeding trunk, or hopper, from the middle of which a rod rises, operating as a piston rod, being acted upon by a lever, worked like a pump-handle. The pis'ton rod passes through the lever, and has a rack, or notches, upon it, which engage with the lever in its descent, but allow it to rise without raising the piston, so that the meat put into the feeding-trunk is forced down by each successive stroke. To facilitate the passage of the meat into the horizontal, from the vertical trunk, I form a spiral excavation in the hollow cylinder, immediately under the vertical trunk; which operates as an inclined plane in producing the desired effect. The cut meat, when it arrives at the extreme end of the cutting cylinder passes out through an opening in the bottom of the box. When the feeding-trunk is to be replenished, the lever may be turned back on its joint, and the piston removed, leaving the opening perfectly free.

When the cutting has been completed, the vertical trunk, with its piston, is used for the purpose of stuffing. To effect this, a shutter, or slider, is slipped into its place where it forms a bottom to the vertical, and cuts off its communication with the horizontal trunk, and a tin, or other tube, of proper size, is fitted into an opening prepared for it on one side of the trunk, at its lower end,

upon this tube the entrail to be stuffed is gathered in the usual way.

To allow the escape of air, this latter tube has a small tube, or opening, soldered on its outside, from end to end. This opening may be semicircular, so as to make but a slight projection on the stuffing-tube. The effect of this will be obvious.

We have not thought it requisite to give the dimensions of the respective parts, as they will vary according to convenience, and will depend upon the power to be applied, and the quantity to be cut. One thing, however, is essential, namely, that the length and size of the cylinders, and the number of knives, be proportioned to the quantity to be eut; but this can be regulated also by the pressure made upon the piston.

APPARATUS FOR HOISTING AND DELIVERING BURTHENS FROM SHIPS, Barnabus Pike, New York.-A frame is to be made by connecting two stout pieces of timber, sixteen or twenty feet long, by cross timber mortised into their ends. The long timbers for a railway upon which to support a carriage, which runs upon friction-rollers on their upper edges. Stout legs are framed into the lower sides of the rail timbers, the carriage has a block and tackle attached to it, by the aid of which, and a windlass, the goods are to be raised from the hold of a vessel. The carriage is then moved along the rails, which extend on to a wharf, and the packages landed. The claim is to the carriage as above described and applied, and the principle and mode of carrying and delivering the burthens.

The whole is clearly described and represented, and at certain periods we have no doubt that such an apparatus will be very useful; but the rise and fall of the tide must, in most places, very much interfere with the employment of it.

XYLOGRAPHIC CHECK PLATES, Charles C. Wright, New York.-The plate from which notes, or checks, are to be printed is to be covered, by means of an engraving-lathe, by transferring, or otherwise, with a very light pattern, consisting of close, but fine, lines. From this the paper is to be printed, say of a light blue, pink, &c. The standing words may then be printed of another colour by any of the known methods. Should chemical means be resorted to for the removal of the fine ground, no human ingenuity, it is said, will suffice to restore and re-unite the lines; and to transfer the two kinds of printing lithographically will be equally impracticable. When used without the printing of standing words, any erasure on the fine ground will be perfectly apparent.

"The invention consists in the prepared ground covering of paper to be used for secu

47

rities written in whole or in part, with or without standing words in the same, of different colour from such ground, substantially as above described."

EVER-POINTED PENCIL CASES, Ellwood Mears, Philadelphia.-The improvement consists in the manner of forcing the lead out of the metal point, and is as follows:The slide or band, which moves up and down the stick, is also capable of a circular motion around it. This slide, or band, has on its inner surface a screw thread, into which the nut of the pin, or wire, used in propelling the lead from the point, works. The band or slide is kept in its place, and pushes out this metallic point by means of two small screws fastened to the lead groove within the case, and rising on each end of the band. Thus by holding the case in one hand and turning the slide or band to the left, or, if preferred, by retaining the slide so as to be immovable, and turning the case to the right, the lead can easily and quickly be propelled from the metallic point.

"What I claim as my own invention, is the method of using the band, or slide, in forcing the lead out of the metal point, instead of the complicated works heretofore in use."

MACHINE FOR FELLING TREES, James Hamilton, New York.-The patentee, after describing the construction of his machine, says, "this applicant in the next place describes the principle of his invention, as follows:-It consists of the combination of a horizontal saw with a crank movement, the saw being of any convenient length, but in the shape of a small segment of a circle, and the length of the crank with which it is directly connected being sufficient for the length of the intended stroke of the saw, the saw being fixed in a frame, and this moving in a centre fixed in another moveable frame which is connected with and moveable upon the same centre as that of the crank; this frame having a horizontal circular movement upon a roller, by force of a weight acting over a pulley, so as to bear the saw forcibly against the material to be sawed, the crank being made to act by any convenient mechanical motion, the whole operating so as to saw horizontally, it being designed for felling trees by sawing through the trunk of a tree horizontally, and near the ground."

Mechanical saws of this description have their uses, as for cutting off piles under water, &c., but they will never enter into competition with the axe of the American woodman; and we are well convinced that in an attempt to use them in this way, his aid would not unfrequently be required to extricate the saw from the kerf in which it would become pinched.

48

NOTES AND NOTICES.

House-Fly Guard.-At the Entomological Society, on Monday, a paper was read by the secretary on excluding the house-fly. The mode adopted was a net made of different coloured meshes of about three-quarters of an inch square, and which, when placed against a window, was found quite effectual in excluding the visits of these troublesome insects from the outside of the room. The same experiment was tried with meshes made of the finest black thread, one inch and a quarter square, which proved to be equally effectual. The approach of wasps was also prevented by the above mode, very few finding their way within the boundary. This was accounted for by an optical illusion in the eyes of the insect, of the highly magnifying power of vision, and the small focal length.

Expensive Tables.-Tables of tiger and pantherwood (different varieties of the citrus) appear to have been first brought into fashion by Cicero, who is said to have given for a single one a million sesterces, i.e. 80721. One belonged to Gallus Asinius, which was valued at 88791. Two, which had formerly belonged to King Juba, were actually sold, one for 97007., and the other for somewhat less. Another, which had been for some generations in the family of the Cethegi, was sold for 11,3007., and in the time of Pliny was accidentally destroyed by fire. The largest ever known belonged to Ptolemy, king of Mauritania: it was four feet and a half in diameter, and four inches thick, being formed of two semicircular planks, so skilfully joined that the place of juncture was not discernible. These tables were generally set in a broad border of ivory.-Mr. Aitken- Trans. Soc. of Arts.

Heat.-At a meeting of the Philosophical Society, Mr. Whewell gave an account of the recent discoveries made by Professor Forbes, and other philosophers, with respect to the polarisation of heat. He stated, that Professor Forbes had recently obtained an additional confirmation of this discovery, by finding that heat, by two internal reflections in a rhomb of rock-salt, resembling Fresnel's rhomb, becomes circularly polarised under the same circumstances as light. It was also mentioned that Biot and Melloni have very recently ascertained that heat acquires circular polarisation by transmission along the axis of a crystal of quartz.-Cambridge Chronicle.

The Danube.-Austria, reflecting that the Danube, the largest river of Western Europe, flows for the greater part of its course through her dominions, and is also her own way to Byzantium, has determined to encourage upon it a line of steamboats. This, in the form of a measure of industry, amounts to a protest against the invasion of the mouths of the river by Russia. There is to be one grand line from Vienna to Smyrna, by Constantinople; and another from Vienna to Trebizonde. The service from Presburg to Smyrna commenced on February 18th, and will employ seven namely, three on the Upper Danube, between Presburg and Dreichora; two on the Lower Danube, between Slela-Cladova, Galatz. and Hirsova; one from Hirsova to Constantinople; and one from Constantinople to Symrna.

boats,

M. Brunel's Mode of Constructing Arches without Centring:-Institute of British Architects, 14th March.-The secretary read a paper explanatory of M. Brunel's mode of constructing brick arches without centring; and a'so explained various experiments of that gentleman, with regard to the insertion of iron hoops in constructions of brickwork in cement. * * * The principle, which was originally adopted, and its efficiency ascer tained, in the formation of the shaft of the Thames Tunnel, is founded upon the cohesive power of Roman cement, coupled with a system of ties, the most eligible substance for which, from a series of

experiments performed by M. Brunel, appeared to be hoop iron. The piers having been constructed in the usual manner, it is proposed to pin or secure to them a mould for the purpose of determining the contour of the arch. A narrow rib may now be carried over, and keyed, using cement (with the occasional insertion of ties). which, by its adhesion to the brick being greater. than the cohesion, enables the arch to be carried to any extent within the limits of the strength of the material. The several arches being in succession, once keyed, they will be in a state to receive the whole of the materials necessary to the completion of the bridge. The bridge of the Santissima Trinità at Florence was particularly adverted to, affording a magnificent example of rubble construction, and the durability of the material. The arches are composed of a mass of irregular stones embedded in mortar, hav ing the consi-tence of a single stone, or of two stones abutting against each other at the crown.Ed. Arch. Mag.

The Mode of Heating the Elephant's House in the Zoological Gardens in the Regent's Park.-A mode of heating has been lately adopted with great success, in a new house prepared for the reception of the elephant in the Zoological Gardens, which appears well adapted for warming churches, chapels, and all other buildings having incombustible floors. It is thus described in the Times:- It consists in a common brick drain, wh.ch is conducted under the floor around the interior of the building. At the commencement of it there is a hole in the floor to the depth of about two feet, such as would be provided for the sink to any common drain; and the other end of the drain, instead of terminating in a sewer, or cesspool, finishes in an upright chimney shaft. A small quantity of fuel is then thrown in what may be called the cesspool at the opening, and lit: the effect is surprising. The downward pressure of the air to the vacuum caused by the fire produces a draught which is equal to that of a furnace. All the smoke being driven down through the fire, is there consumed, and, with the body of heat, rushing through the horizontal drain for the length of 110 feet before it reaches the upright or chimney shaft, all, or nearly all, the heat transudes through the floor, from which it ascends with as pure a warmth as that from the sun. We understand there is a floor of concrete nearly a foot in thickness over this drain, which, with the large quantity of humidity contained in it, must materially lessen the transmission of the heat: still the warmth is considerable."-Arch. Mag. for April.

Sir, I shall be greatly obliged to any of your correspondents who will, through the medium of your pages, inform me how the blowing-fan is applied for the ventilation of buildings, and if one is sufficient for two or three floors, what would be considered the most efficient situation, and the me thod of communication. Your early insertion will confer a favour on, Sir, yours respectfully, T. V.

Patents taken out with economy and despatch; Specifications, Disclaimers, and Amendments, prepared or revised; Caveats entered; and generally every Branch of Patent Business promptly transacted. Drawings of Machinery also executed by skilful assistants, on the shortest notice.

LONDON: Published by J. CUNNINGHAM, at the Mechanics' Magazine Office, No. 6, Peterborough-court, between 135 and 136, Fleet-street. Agent for the American Edition. Mr. O. RICH, 12, Red Lion-square. Sold by G. W. M. REYNOLDS, Proprietor of the French, English, and American Library, 55, Rue Neuve, Saint Augustin, Paris.

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Fleet-street.