Stephenson's? The working plans having gone forth with my name alone attached to them, and from my being recognised as the acting engineer, might not the whole blame have been conveniently thrown on me in case of failure?

"It was not, however, on any of these grounds that I was induced to resign my appointment; for there had not then occurred any opportunity where I conceived it necessary to have my position publicly recognized; and I had always believed that when the proper time came, Mr. Stephenson would be the first to establish that position, and acknowledge the services I had rendered. The recognition was, however, very shortly afterwards denied me. The first Conway tube having been completed, and the success of the principle established, I conceived that the construction of the remaining tubes simply required a close attention to the system of construction already adopted, and therefore might safely be entrusted to those gentlemen whose constant presence during the building of the first tube had rendered them thoroughly acquainted with the whole details of the work, By such an arrangement, moreover, the Company would save the amount which had hitherto been paid for my services, and I should be enabled to devote my time to other pursuits which I had neglected for this work, and which now urgently demanded my attention. This was one reason for my retirement; but what chiefly led me to this decision, was the position assumed by Mr. Stephenson, his public misrepresentation of the position I held under the Company, and his endeavour to recognize my services as the labours of an assistant under his controul, and acting entirely under his direction. Had Mr. Stephenson, in his public address, done me the justice to state my independent claim to some of the most important principles observed in the construction of the tubes, I might perhaps have continued my services until the final completion of the whole undertaking; and, most assuredly, this work would never have come before the public. I now appeal to the preceding pages of this narrative, whether Mr. Stephenson's assertions are borne out by the simple statement of facts? I have overstated nothing, concealed nothing, and the reader is left to draw his own conclusions from these facts, after having become acquainted with the course pursued by Mr. Stephenson; which I will, in conclusion, concisely relate.' p. 171.

Mr. Fairbairn proceeds then to give an account of a public dinner to celebrate the completion of the Conway Bridge, which took place on the 17th of May, 1848; on

which occasion it was Mr. Stephenson first openly assumed that position in regard to Mr. Fairbairn and the undertaking, which has made the present appeal to public justice necessary. Mr. Stephenson's speech was confessedly a studied affair- he had announced beforehand that he would avail himself of the opportunity of "setting the question at rest;" but for all that it does not take Mr. Fairbairn many words to demolish it utterly.

"The inaccuracies, both as to facts and dates, in this statement of Mr. Stephenson, are very numerous. It simply requires a reference to the short description of the Ware Bridge, p. 113, and to the drawings, to disprove the assertion, that it is a thin tubular bridge, although not precisely the same as the present, yet in principle precisely the same;' and it can easily be shown, too, that considering the Ware Bridge as a simple girder bridge, it is exceedingly defective in design. Is there anything new in this application of wrought-iron plate girders?

As well might it be said that the combination of wrought-iron deck beams, so many years applied in iron ships for the support of the decks, is a 'counterpart of the proposed cellular top for the Britannia tubes.', I really cannot but regret that Mr. Stephenson, whose name will be always associated with the grandest bridge that has ever been constructed, should have committed himself in making such an erroneous assertion as that it was by reviving and extending his original conception of this imperfect structure at Ware, that he was led to originate the bridges crossing the Conway and Menai Straits.

"Mr. Stephenson's remarks further admit of the disingenuous construction that his scheme was matured before the Bill for the Chester and Holyhead Railway was passed by Parliament, and before I was consulted, and that he was at that early period acquainted with the present design of the bridge. He refers to the incredulous glances which were directed towards him when the description of the bridge was explained to the Committee; and intimates, that it was not until the Bill had been obtained, and it became necessary to commence, that he requested my assistance' Now, my advice was asked by Mr. Stephenson before his evidence to the Parliamentary Committee was given, and he announced his idea to that Committee strengthened by more than one opinion of its feasibility. Let the reader turn again to the earlier letters of the correspondence, and he will find of what a crude and dangerous scheme that idea con

ANCIENT WORK ON MECHANICS.

Mr. Ewbank, in his valuable work on Hydraulics, page 285, refers to the celebrated work of Ramelli, and states that he had not been able to procure a copy of the work. It may be a public service to mention that a copy of this rare work, originally belonging to the Library of the Jesuits at Quebec, which was purchased at its sale when the Order was suppressed, after the capture of Canada by the English, subsequently fell into the hands of the late Simeon De Witt, and was sold a few years ago by me to the Patent Office. It is the only copy of the work that I have ever heard of as being in the United States, and is an extraordinary exposition of the advance of mechanic art at its era.

The work is in folio, 338 pages letterpress, duplicated, and contains Italian and French descriptions of 195 different engines or combinations of engines in military or isometrical perspective, delineated perfectly and lucidly; each engraving, folio page, devoted to a separate engine or machine, ornamented with appropriate embellishments of building, landscape, or fortress, with men and animals in proper position of service in connection with the subject of the drawing.

The frontispiece represents the author in military undress at a table, with his dividers in hand, measuring the plot of a fortress on a plan lying before him, the picture being completed by engineering instruments, armour, &c.

The title page is :-" Le diverse et artificiose machine, del Capitano Agostino Ramelli, del ponte della Tresea Ingegniero del Christianissimo Re di Francia et di pollonia. Nelliqualli si contengono varii et industriosi monumenti degni degrandissima speculatione per caverne beneficio infinito in ogni sorte d' operation. Composto in lingua Italiana et Francese. Aparagi in casa del autore co privilegio del Re. 1588."-Scientific American. W. H.

SPECIFICATIONS OF ENGLISH PATENTS ENROLLED DURING THE WEEK ENDING 5TH OF JULY, 1849.

MOSES POOLE, London, gentleman. For improvements in the manufacture of heels for boots and shoes, of swivels, of bag fastenings, of revolving furniture, and of the connection of pipes for gas and other fluids. (Being a communication.) Patent dated December 28, 1848.

The improvements sought to be secured under this patent consist in making the two pieces of attachment with male and female screws, so that the thread or worm of the male screw may pass above that of the female screw, and serve as a stop to prevent disconnection, unless when turned in the reverse direction with a backward motion.

Claim.-Making the screw fastenings of heels for boots and shoes, of swivels, of bag fastenings, of revolving furniture, and of the connection of pipes for gas and other fluids as before described.

WILLIAM DINGLE CHOWNE, Connaughtplace West, M.D. For improvements in ventilating rooms and apartments. Patent dated December 28, 1848.

Dr. Chowne states that his invention consists in the application to the ventilation of apartments of the syphon, placed with the legs upwards, which will have the effect of causing the atmospheric air to descend the lower leg and escape through the upper leg-the reverse of what takes place when the syphon is immersed in water or other liquid. For this purpose he proposes to employ the chimney as the long leg, and to construct a channel in the wall, or to affix a pipe thereto, which opens into the bottom of the chimney and into the apartment at top. The fireplace is, of course, kept closed by a screen or the tap of the registry stove. The short leg of the syphon may be fitted with one or more branch pipes, and may have the end, opening into the room, concealed by an open cornice, or it may be hidden by, or made to form part of, the architectural ornaments of the room. When fixed gas or oil lamps are employed, separate pipes are used to convey the products of combustion to the chimney. The same principle is proposed to be applied to the ventilation of mines.

Claim. The patentee does not confine himself to the precise details of the specification, so long as the peculiar character of his invention is retained, and the principle of what he calls the "Atmospheric Sy. phon" is applied by suitable apparatus or means to the ventilation of rooms or apartments.

CHARLES Low, Roseberry-place, Dalston, gentleman. For improvements in smelt

ing copper ore. Patent dated December 28, 1848.

This invention consists in the introduction of currents of atmospheric air into the smelting furnace, so that they may pass above the metal and below the flames. The air being thereby decomposed, and parting with its oxygen, facilitates the separation of the copper from its oxide.

The currents of atmospheric air may be introduced through apertures constructed in the bridge or in the sides of the furnace.

No claims are made in this specification. GEORGE FERGUSSON WILSON, Belmont, Vauxhall, gentleman, and CHAarles HumPHREY, Manor - street, Old Kent-road, merchant, for improvements in the production of light by burning oleic acid in lamps, and the construction of lamps and manufacture or preparation of oleic acid for that purpose. Patent dated December 28, 1848.

The patentees remark that oleic acid, which is produced in the manufacture of stearic acid by the saponification of fatty matter, and known in commerce as tallow oil, contains so many impurities as to render it unfit for burning in lamps, and is moreover so easily decomposed by the heat of the burner tube, as to produce a thick pitchlike substance, which has the effect of extinguishing the light. Now the object of the present improvements is; firstly, to purify the oleic acid, by mixing with it dilute sulphuric acid, and agitating it, without, however, applying heat, as has hitherto been customary, and redistilling it, whereby the acid will be obtained in a state of great purity; secondly, to maintain a portion of the wick between the bottom of the flame and the top of the burner tube, unblackened, to prevent the heat of the flame from decomposing the oleic acid, so as to produce the thick pitch-like substance before mentioned, by the employment of a plate, with a central hole, which is placed over the wick, and has the effect of directing currents of air against the said part of the wick and upwards through the chimney.

No claims are made in this specification. ISRAEL KINSMAN, late of New York, but now of Ludgate-hill, merchant, for improvements in the construction of rotary engines to be worked by steam, air, or other elastic fluid. Patent dated Dec. 28, 1848.

The improvements in rotary steam engines, described by Mr. Kinsman, have reference to engines of a peculiar construction, for which he formerly obtained letters patent. The characteristic feature of the engine is the employment of a fixed cylinder, and of a steam wheel rotating within it. The steam wheel is furnished

with five pistons, connected together by packings, concave to the inside circumference of the cylinder, which is fitted with four steam stops, which are kept in constant contact with the periphery of the wheel, and provided with toes, or projections which embrace both sides of the pistons, and prevent the escape of steam. At each side of the cylinder there are two annular chambers which serve the purpose of steam chest and exhaust port. The steam stops are worked by cranks driven by toothed gearing from the shaft of the rotating steam wheel, so that they may be kept in contact with its periphery, and not worked by it. The cut off valves are worked by eccentrics, so that they may be governed by the motion of the steam stops.

The details of Mr. Kinsman's improvements could only be rendered intelligible by a careful collating of his two specifications, and for that we have neither space nor inclination.

Claims.-1. The mode of operating the steam stops, or abutments, by a crank motion derived from the rotation of the steam wheel substantially as described, when this is combined with a rotating wheel, the form of the periphery of which is such as would be generated by the motion of the steam stops which are kept in contact with the periphery of the piston wheel, but not operated upon thereby.

2. Making the ends of the steam stops with toes, or projections, which embrace the sides of the pistons and extend within the periphery of the piston wheel, when this is combined with the recesses or grooves, to prevent the escape of steam through them.

3. The employment, in combination with the rotating wheel, of cut-off valves, which are governed by the motion of the steam stops.

4. Packing the piston wheel, the steam stops, &c., with metal rings, provided with holes corresponding to the induction and eduction ports.

5. Packing the piston wheel by a metal ring, kept in position by means of adjustable

screws.

WILLIAM KNApton, York, ironfounder, for certain improvements in the mode of manufacturing gasometers or gasholders. Patent dated January 3, 1849.

The object of these improvements in gasometers is to supersede the use of water tanks. The top and bottom of each gasometer is made of angle iron, to which iron plates are riveted; and the side is composed partly of iron and partly of some flexible material, rendered impermeable to gas, so that as the gas escapes the area of the holder may be

decreased.

The bottom of the gasometer is supported upon cast-iron columns, and the top is suspended from weighted chains, as usual.

Claim.-The manufacturing of gasholders or gasometers of flexible and inflexible materials.

WILLIAM EDWARD NEWTON, Chancerylane, C.E., for certain improvements in steam engines. (Being a communication.) Patent dated December 28, 1848.

1. The patentee states that his foreign correspondent has remarked, that in all beam steam engines, in which the steam is made to work expansively, the resistance of the impelled body does not decrease in proportion to the decrease of the pressure of the steam as it should do, in order to the economical application of the expansive principle. If the steam, he says, be cut off at one-fourth of the stroke, half the force of the steam will be expanded in driving the piston one-eighth of the stroke, while the crank will have been moved only one-third of a semi-revolution from the dead point; and the other half of the force of the steam will be expended in driving the piston the remainder of the stroke, and have to drive the crank through two-thirds of the semi-revolution. He therefore proposes to place the centre of the axis of the crank shaft in a plane nearer to the axis of vibration of the beam, instead of in a plane midway between a plane passing through the centres of the connection of the connecting rod at the extremities of each vibration, and a plane parallel to this one, and passing through the centre of the connection of the connecting rod when the beam is midway from the extremity of each vibration, that is to say, in the first plane. He further proposes to employ a pair of engines, the cylinder of the one being much larger than than that of the other, and having their pistons respectively connected to the short ends of two beams. The long ends of the beams are connected by rods, each equal to two and a half times the length of the crank, to two cranks keyed at an angle of 180°, upon a shaft, placed upon the principle before described. The steam enters the small cylinder at top from the boiler and drives its piston downwards, and, at the end of the stroke, communication is opened with the larger cylinder, into which steam passes and forces its piston down by its expansion only at the same time that communication is established with the bottom of the small cylinder, so that as its piston is moved upwards the pressure of steam on both sides is balanced. The bottom of the large cylinder communicates constantly with the condenser; and when its piston has arrived at the end of its stroke, communication

is established between the top and bottom of the large cylinder and the bottom of the small one, so that when the piston of the latter is driven down the steam will be exhausted from its underside, so that it may encounter no resistance, and the piston of the large cylinder will move upwards in vacuo. The cut-off and slide valves are worked by eccentrics keyed upon the shaft, and possess no characteristic features that need description.

2. The improvements in steam engines employed in the propulsion of vessels, consist of certain arrangements for condensing the steam without allowing the condensing water to come into contact with the water of condensation, and are as follows: A number of tubes are inserted into two diaphragms, and supported in a horizontal cylinder. One of the diaphragms is attached to a flanch of the cylinder, so as to leave on one side a chamber between its head and the ends of the tubes. The other diaphragm is fixed to a conical ring attached to the cylinder, so as to leave a chamber on that side also. The object of this conical ring is to allow for the expansion or contraction of the tubes: the first chamber is divided into two by a horizontal partition, and the top portion communicates with the exhaust passages of the engine, and with the safety valve of the boiler, while the lower portion communicates with the air or feed pump. A rotary pump, worked by an auxiliary engine, independently of the propelling engine, draws the water from the outside through pipe placed beneath the water line, and injects it at the bottom of the condenser, which is partially divided by a horizontal partition, so that the condensing water flows over the lower half of the tubes from front to back, and then from back to front over the upper half of the tubes, after which it escapes by an eduction pipe. The steam, whether from the exhaust of the engine or the boiler, enters the tubes, and as it flows through becomes cooled-the coldness of the condensing water increasing with the decrease of the temperature of the steam, until it at last becomes condensed and passes to the feed pump.

Claims.-1. Placing the centre of the axis of the crank, in beam engines where steam is applied expansively, nearer to the centre of the axis of vibration of the beam, on the principle before described, and for the purpose of obtaining a more regular mechanical force upon the crank from the expansion of the steam.

2. The use of two engines, having their cranks placed on a shaft opposite to one another, or at an angle of 180° when the crank shaft is located as described.