sea voyages, copper would last about seven years, whereas iron would last only about four years; what would be the proportion in fresh water?-In fresh water for steam navi. gation, the boilers last about seven years.

895. The iron boilers are you speaking of? -Yes; copper boilers are not used in fresh water; there is no inducement to use copper boilers in fresh water, because iron lasts so long.

896. Are copper boilers used in salt water? -Yes.

898. In preferring copper boilers to iron ones for salt water, do you make an allowance for the difference of the tensity in copper, and the different temperature in the boiler; that copper diminishes in tensity as heat is applied, and iron does not?-We find no difference in that respect; the copper and the iron are of the same thickness, and the question turns entirely upon their durability.

JECK'S OCREAN, OR BOOT-WEARERS'

ASSISTANT.

B; C is a handle on the top of the rod D, fastened with the sockets F; E is an instrument attached to the standards A for drawing off boots; G are hooks to receive the boot-straps previous to their being drawn on. The following are the patentee's directions for the two operations of pulling on and off:

Pulling on.-The boots being fixed in the frame, and the hands resting on the handles, it is necessary to place the toes downwards into the top of the bout, and, by inclining the weight of the body on that leg, the boot is drawn on. Should it be a very tight boot, it is only necessary to draw the handles upwards at the same time, while the other foot is made to rest on the bottom of the frame, to enable any one to perform the operation with surprising ease. - The boots should be hung so as to suit the wearer's height, but in all cases high enough to be clear from the bottom of the frame.

Pulling off.-The hands being placed as before, the instrument attached to each side of the machine is so contrived, that the boot is easily drawn off by raising the leg, without the assistance of any one to bear on the toe.

The above engraving represents a new patent contrivance, which has recently made its appearance in the shops, and which, though it has much the air of a fashionable conceit, with a most unprepossessing, though legitimatelyenough-constructed name, (ocrean froin ocrea, the Latin for boot), is really a very useful invention. Its object is to facilitate two operations, which, to gentlemen fond of a tight fit, and to all gentlemen of a certain age, are commonly extremely troublesome; namely, pulling on and off their boots.

AA are standards attached to the plate

NOTES AND NOTICES.

Soldier's Cloak.-Captain Dickson, 25th regiment, has invented a cloak weighing but 14 oz., for general use in the army. It is intended to fit on between the soldier's knapsack and mess-tin, and will effectively keep him from wet.-Hibernian United Service Journal.

The Poor Working Colliers.-The newspapers announced last week the appointment by the House of Commons (on the motion of Mr. Pease), of a Select Committee to inquire into the causes of the frequent explosions in coal-mines; and this week they furnish one of the most melancholy proofs of the necessity of that inquiry, which has ever yet come under our notice :-On Thursday, the 18th inst., an explosion took place in one of the Wallsend pits, known by the name of the Church Pit, or Russell's Old Wallsend, by which more than a hundred persons, men and boys, are supposed to have been killed The Davy-"Safety Lanip" no longer--was in full use in the pit, which has been the scene of this appalling destruction of human life. We may now surely hope to see the real worth of this much-boasted contrivance placed by the labours of the House of Commons' Committee in its proper light.

Roberts' Safety Lamp.-On Friday evening last a lecture was given by a Mr. Taylor, at the Eastern Literary and Scientific Institution, the object of which was to show, by actual experiment, that the lamp hitherto used in coal-mines, and invented by Sir H. Davy, is dangerous and insecure, and that a lamp invented by Mr. Roberts is perfectly safe and free from the defects which tender the lamp of Sir H. Davy not to be depended upon by the

miners. Mr. Roberts, who has already received several medals from the Society for the Encouragement of Arts, Manufactures, and Commerce, was in attendance, and produced the lamp invented by Sir H. Davy and his own lamp, and assisted Mr. Taylor in the lecture and in the experiments. Mr. Taylor commenced his lecture by explaining the nature of combustion. He described carburetted hydrogen, or fire-damp. He then detailed the doctrine of flame and the progress of combustion. He pointed out by experiments the properties of nitrogen, carbonic acid, and oxygen, and showed the manner in which the safety of the invention of Mr. Roberts is connected with them. Mr. Roberts then displayed his lamp, and described the manner in which it differs from that of Sir H. Davy. He showed the defects of the lamp of Sir H. Davy, the insecurity it affords to the currents of carburetted hydrogen or fire-damp, the dangers arising from the ignition of the small particles of coal adhering to the wire gauze by which it is surrounded, from the oil clinging to the sides of the gauze when the lamp is npset or held in a horizontal position. His own lamp he showed to be free from the two last-mentioned defects. It is surrounded by a double tube of wire gauze, and also by a glass chimney, and is so contrived that a current of carbonic acid air or nitrogen passes continually between the external atmosphere and the flame of the lamp; the flame alone can burn, and any ignition from external explosive current of fire-damp is repelled by the carbonic acid or nitrogen, by which combustion is immediately destroyed.-Times.

Sir John Soane and the Institute of British Architects." In your notice (p. 224) of the opening meeting of this Institution, you omit to mention a very auspicious incident which marked the close of the proceedings. The President, Earl de Grey, stated that he had a most gratifying letter to read from Sir John Soane, who had not only distinguished himself as an eminent architect, but as a munificent patron of the art to the cultivation of which his life had been devoted. It was a letter, announcing a donation of 7504., in his own name and that of his grandson, John Soane, Esq., for the general purp ses of the Institution. The noble President himself proposed a motion for a vote of grateful acknowledgment to Sir John Soane, which was carried by acclamation; and a special meeting was ordered to be convened for an early day t take into consideration the mode in which this noble gift shall be appropriated."-We cordially congratulate the Institution on this most liberal and well-timed donation. The omission of it from our notice arose from the late period of the evening at which it was announced.

London and Birminghum Railway." The work through Tring Hill is proceeding very well, and, I may say. rapidly. A "temporary bridge" has been constructed across the canal at Seabrook, to carry the fearth over (the embankments being finished as far as there.) I understand it is not the intention of the Company to put up the permanent bridge till all the earth shall have been carried over. But the foundations for it have been put in some time. The top is to be of iron. Mr. Townsend has lately been laying down a fresh set of rails (parallel wrought-iron ones,) in lieu of the common cast-iron, and a new set of waggons have been put on the work. The temporary bridge over the canal is something like a bridge when compared to that which was put over the canal at Wolverton, and pulled down by the Canal Company. (By-the-bye, think a vote of thanks ought to have been passed by the Railroad Company, and forwarded to the Canal Company, thanking them for their unbounded kindness in destroying a bridge which must have broken by its own weight, and occasioned, probably, a great loss of life) By what I can learn, they get on very badly in that quarter. Mr. Towns.

and will complete his part, before the others are well begun. He keeps his men very steadily at work."-K. Tring, 20th June, 1835.

Mr. Collier's Boiler.-We regret to find that we made a mistake in our last Number with respect to the transaction between the Lords of the Admiralty and Mr. Collier (through a misreading of the manuscript of our informant), which is calculated to place Mr. C. in a worse light before the public than he deserves. We now take the earliest opportunity of apologizing for, and correcting, it. The real facts of the case we understand are these. The Lords of the Admiralty did pay Mr. Collier the full price (2,000l., we believe) for the boiler fitted on board the Meteor; but after its failure and removal from that vessel, Mr. Collier applied to their lordships for leave to repurchase it at the price of old metal, which was granted. The sum for which it was appraised back to him (funnel included) was 150., being at the rate of 4l. 10s. per ton.

A New Steam-Carriage, constructed by Mr. Field (of Messrs. Maudslay's and Field) made a trial excursion on Saturday last, carrying Sir H. Hardinge, Sir H. Parnell, and a select party. In the course of its journey, it went up Denmark Hill, and performed its distance 94 miles in 44 minutes. From a Correspondent.

Artificial Marble or Stone Coffins.-These coffins are composed of a cement two thirds of an inch in thickness, solid and hard, yet light in its texture, and on the outside polished, and afterwards varnished. This glazing or varnish may be an imi. tation of mahogany, maple, rose, or any other elegant wood. The coffins, it is presumed, are to be made with the lids separate. After the body is placed in it, a thickness of cement is to be laid on the edge of the coffin, to connect the lid, leaving a small opening, to be used temporarily until the air is exhausted by a receiver. This opening also being filled in, the whole is perfectly air and watertight. The interior being deprived of air, decomposition of the body, and the breeding of those germs of insects which are supposed to be inherent in our flesh, cannot, of course, go on, and must be suspended. The invention far excels the compli cated process of embalming, and we doubt not it will be entirely substituted for destructible wood, and come into general use, not only for coffins, but for all kinds of vessels and receptacles in which it is desirable to preserve the contents from dampness and the external air-thus, for records, public do. cuments, books transported to great distances over the sea, &c. In these air-tight coffins, Mr. White proposes to insert in the lid, over the face of the corpse, a thick plate of transparent glass, while the cement is soft, and which thus on hardening, becomes a part of the lid.-New York American.

Lord Brougham's Patent Law Amendment Bill, has been before a Select Committee of the House of Lords, and referred back to the same Committee for further consideration. We understand that it has met with great opposition from some of the law lords of the House, and is likely to come out of the Committee quite an altered affair. We shall therefore postpone our intended observations upon it, till we see what shape it definitively takes.

Patent Law Amendment Petitions.-Our advice to our friends at Leicester, and to all-intending petitioners, is to wait til a combined effort for a real reform of the existing system can he made with a better prospect of success than at this fagend of the Parliamentary season.

Fulton's Grand Orrery.-We recommend to the attention of such of our readers as are astronomically inclined-the juveniles of the class in particular-a grand Orrery, which is now exhibit ng in Bond-street, by a Mr. Fulton, from Edinburgh. A Committee of the Society of Arts of Scotland, t

whom it was referred for examination, reported of it in the following terms :-"The particular Orrery under review merits attention from the magnitude of the design, and from the accuracy of the performance. So far as mean annual motion is concerned, it approaches as nearly to perfection as is needed in an instrument of the kind. As an instrument for communicating a general idea of the Planetary System to those who have never had their attention directed to Geometry, the Orrery is unrivalled; and on that account it appears to your Committee that its framer merits a high mark of the Society's favour."-The Orrery is not transparent, but opaque, and is exhibited in daylight, having the Sun and all the Planets, with their Moons, represented by so many gilded globes, ali of which revolve in their true (relative) periods. It contains upwards of two hundred movements, effected by means of one hundred and seventy-five wheels and pinions, most of which are exposed to view; and differs from all former Orreries, in exhibiting the motions of all the secondary Planets with the same accuracy as those of the primaries. Our esteemed correspondent, Mr. G. Henderson, of Liverpool, whose practical familiarity with ma chines of this description entitles his opinion to great weight, says of Mr. Fulton's Orrery, in a letter which we some time ago received from him: "It is one of the most comprehensive of plane. tary machines which has ever come under my notice; its usefulness in the way of illustrating the motions of the planetary orbs cannot be over estimated; and I will venture to say, that the tyro in astronomical pursuits will receive a more correct idea of the harmony of the Solar system from Mr. Fulton's Machine, in a few minutes, than by study. ing all the Astronomical treatises that were ever written."

B.'s right to his invention will not be endangered by exhibiting the results of it mere y, as long as he can manage to do so without making public the modus operandi.

LIST OF NEW PATENTS, GRANTED BE. TWEEN THE 22D OF MAY, AND 22D OF JUNE, 1835.

Thomas Fleming Bergin, of Fair View Avenne, Dublin, civil engineer, for certain improvements in the method of suspending and adjusting the bodies of railway and all other wheeled carriages. May 27; six months to specify.

John George Bodmer, of Bolton-le-Moors, Lancaster, civil engineer, for certain improvements in machinery for preparing, roving, and spinning cotton and wool. May 27; six months to specify.

John Losh, of 8, Crescent, Carlisle, for an improvement in the surface or pattern roll of the machines used in printing calico and other goods, commonly called a surface-printing machine, and in the mode of working the said rolls. May 30; six months to specify.

Joseph Nye, of St. Andrew's-road, Southwark, for improvements in pumps and instruments or ap. paratus for conveying fluids into, and withdrawing them from, cavities of human and other animal bodies, part of which improvements are also applicable to other pumps. June 2; six months to specify.

John Malam, of Kingston-upon-Hull, civil engineer, for certain improvements in gas-meters, and in the apparatus for generating gas for illumination. June 2; six months to specify.

William Wilkinson, of Lucas-street, Commercialroad, engineer, for a certain improvement or certain

improvements in the mechanism or machinery, by which steam-power is applied to give motion to ships or other floating vessels in or through water, June 2; six months to specify.

Richard Phillips, of New Kent-road, Surrey, lecturer on chemistry at St. Thomas's Hospital, for his invention of certain improvements in the process of manufacturing sulphate of soda. June 4; six months to specify.

James Leman, of Lincoln's-inn-fields, gentleman, for the making, mixing, compounding, improving, or altering of soap, being a communication from a foreigner residing abroad. June 4; six months to specify.

Bennet Woodcroft, of Ardwick, Lancaster, gentleman, for improvements in printing calicos and other fabrics, whether manufactured of cotton, silk, wool, or linen, or of all, or any two or three of those materials. June 4; six months to specify.

Thomas Hancock, of Goswell street-road, waterproof-cloth manufacturer, for an improvement orimprovements in air beds, cushions, and other articles manufactured from caoutchouc or Indian-rubber, or of cloth or other flexible materials, coated or lined with caoutchouc or Indian-rubber. June 4; six months to specify.

Joseph Whitworth, of Manchester, machinist, for certain improvements in machinery, tools or appa ratus, for turning, boring, planing, and cutting metals, and other materials. June 11; six months to specify.

Elias Carter, of Exeter, for an improved apparatus for regulating the supply of gas to the burners, and for the stopping off the same, applicable also as a cock in drawing off or regulating the flow of other fluids. June 22; six months to specify.

John William Fraser, of Ludgate-hill, for im provements in apparatus for descending under water. June 22; six months to specify.

James Mitchell, of Truro, Cornwall, for an improved process in smelting argentiferous ores. June 22; six months to specify.

Patents taken out with economy and despatch; Specifications 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.

Mr. Needham may obtain the Number he wants through his bookseller.

Communications received from Mr. HaddrickIver Maciver-Scrutator Mechanicus (2dus)-An Inquirer-J. P. A.

Our Publisher will give One Shilling and Sixpence for copies of the Supplement to Vol. IX.

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. G. BENNIS, 55, Rue Neave, Saint Augustin, Paris. CUNNINGHAM and SALMON, Printers, Fleet-street.

TILLEY'S NEW METALLIC FIRE-ENGINE.

Sir,-After witnessing the introduction of boats, bridges, and churches of cast-iron, with many other extraordinary applications of this highly-useful material, your readers will not be much surprised at the introduction of cast-iron fire-engines, and this material enters pretty largely into the machine I am about to describe.

It is well known that hot climates exercise a most injurious effect upon all things constructed of wood, especially if occasional moisture assists the operation of the heat. Among other machines which manifest the existence of this destructive influence, fire-engines are particularly liable to dilapidation; sometimes saturated with water, and then exposed to parching dryness-laid by unheeded until required for use-no wonder they are so often found unserviceable. To obviate the serious inconvenience arising from this cause, and to render the fire-engine, as far as possible, proof against the effects of climate, Mr. W. J. Tilley, engine-maker, Blackfriarsroad, London, has constructed a fireengine entirely of metal, of which fig. 1 is a side, and fig. 2 an end-view. The same letters of reference apply to both drawings.

aaa are three cast-iron standards, fixed upon a quadrangular floor or framework bb, of the same material. cc is the main axis working in brass bushes on dd are the two brass the tops of aa. cylinders or pumps. e is the air-vessel, of copper; f is the suction-pipe; and g the delivery-pipe. A chamber h contains the suction-valves, the delivery-valves being placed in a similar chamber i in front of the cylinders. kk are the handles, made of sheet-iron rolled up, which, by means of the cross-levers,

The whole is mounted on four castiron wheels, and has rather a light and elegant appearance.

In the construction of this engine not a particle of wood is employed; the valves, the pistons, and, in fact, every part is of metal.

This engine exhibits, in a very pleasing manner, the situation of all the working parts, which, in fire-engines of the ordinary kind, are enclosed from view; but a most important advantage consists in the facility with which any little derangement in the machine can be seen 'and remedied. The valves, which are almost the only parts liable to get out of order, can be got at immediately, as it is only necessary to unscrew and remove the cover of the valve-chambers, to examine and repair any obstruction in this part of the machine.

The durability of this description of fire-engine, and its fitness for all foreign

stations, especially in hot climates, must be so great, that for such services I have no doubt they will in time supersede all other engines constructed of so perishable and uncertain a imaterial as wood.