tion following must admit of a more easy solution than can now be given to it, viz. with how small a force, and in how short a space of time, can we get rid of nine or ten thousand cubic feet of air? Further, the clumsiness of the chamber which is mentioned as requisite for that purpose, to say nothing of the expense, must be one more great objection; and it requires but a very small portion of common sense to perceive, that in prac tice, something rather more substantial than sheet-iron would be requisite.

If I have taken a wrong view of the matter, I hope Mr. Carey will not neglect to put me right, as the subject is a very important one: had he favoured us with a slight sketch, all obscurity would have been done away.

The adoption of Mr. Wharton's plan of towing boats through canal tunnels, described in No. 675 of the Mechanics' Magazine, would necessarily be attended with enormous expense; for should the traffic be any thing like considerable, it would be requisite for some five or six engines to be always in readiness at each end of the tunnel; to take in tow the boats as they successively come; whereas, one stationary engine of sufficient power would answer every purpose; and, likewise, would not be the means of adding to the impure gas carried into the tunnel, unavoidably disengaged during combustion.

I am, Sir, truly yours,

Gayton, Jan. 18, 1937.

J. L.

VENTILATION OF APARTMENTS.

Sir, I wish to offer a few remarks on the subject of a plan by which the foul and unwholesome air which is generated in sitting-rooms may be immediately carried off, and a constant supply of fresh atmospheric air insured. As rooms are at present built, it is quite clear that the only portion of air in them which can undergo any change is that towards the lower part-in fact, not extending above the chimney-piece. When the doors and windows are closed, the only current

is up the chimney, and that current acts upon the lower stratum of air alone, leaving all the upper surface, which is foul and unwholesome, hanging from the ceil

ing like an infectious cloud, and so low down as to be inhaled by those who are present. The heated air which rises towards the ceiling has no means of escape; it there hangs confined without being at all influenced by the under current up the chimney. It appears to me that this evil may be easily overcome by simply making an opening into the chimney at the upper part towards the ceiling, by which you will immediately cause an upper current into it, in consequence of the partial vacuum produced by the heat from the fire. By this plan you ensure two constant currents of air in a room, extending their influence to every part of it, causing that which is breathed to be not only more refreshing, but much more wholesome. I propose to have this opening which I speak of so formed, that it may, in fact, be very ornamental. A square or circle, for instance, of two feet diameter, the interior being composed of a description of open or trellis-work, representing some tasteful design. It might be so arranged as to be capable of being closed when required. The smell arising from a half-extinguished lamp would after rising towards the ceiling be received into this upper current, and immediately carried away through the trelliswork up the chimney; so also all the hot air, the exhalations from the dinner-table, and all others of a noxious quality, would after rising upwards be carried off, and give place to a fresh supply. That this effect would be produced is quite clear; and it would, if adopted, tend, no doubt, to the comfort as well as the health of all, particularly of those who spend much of their time in doors.

If you think proper to give these suggestions a place in your Magazine, I may trouble you with some further ideas connected with the same subject, which, at any rate, is worthy some attention, as it relates to the health and comfort of the whole mass of society.

There is another advantage which would accompany this double current of air-that of preventing any chimney smoking. The united power of the two upward currents would have the effect of resisting the force of any single current whose inclination would be to descend.

I am, Sir, yours, &c.

M. C.

LIST OF ENGLISH PATENTS, GRANTED BETWEEN THE 25TH OF DECEMBER, 1836, AND THE 27TH OF JANUARY, 1837.

Hamer Stansfeld, of Leeds, York, merchant, for an invention, being the application to certain machinery of a tappet and lever action to produce a vertical or horizontal movement through the medium of ropes or bands working over, under, or round pulleys; being a communication from a foreigner residing abroad. Dec. 30; six months to specity.

William Cooper, of Picardy-place, Edinburgh, glass-merchant and stained glass-manufacturer, for an improved method of executing ornaments, devices, colours, or stains on glass. Jan. 10; six months.

Robert Griffiths, of Smethwick, Birmingham, machine-maker, and Samuel Evers, of Cradley Iron-Works, Stafford, iron-manufacturer, for improvements in the manufacture of burrs or nuts for screws, Jan. 11; six months.

Henry Adcock, of Summer-hill-terrace, Birmingham, engineer, for certain improvements in the construction of the furnaces employed in the reduction of iron-ores and other metallic ores, as also in some of the processes of the iron manufacture of other metals, such furnaces being applicable to other purposes. Jan. 11; six months.

James Gardner, of Banbury, Oxford, ironmonger, for certain improvements in cutting Swedish and other turnips, mangel-wurzel, and other roots used as food for sheep, horned cattle, and other animals. Jan. 11; six months.

Charles Sheridan, of Ironmonger-lane, London, chemist, for improvements in the manufacture of soda. Jan. 11; six months.

John Paul Neumann, of 81, Great Tower-street, London, prussiate of potash-maker, for improvements in the manufacture of prussiate of potash and prussiate of soda; being a communication from a foreigner residing abroad. Jan. 11; six months.

George Goodlet, of Leith, Edinburgh, merchant, for a new and improved mode of distilling from wash and other articles; also applicable to general purposes of rectifying, boiling, and evaporating or concentrating. Jan. 11; six months.

Francis Gybbon Spilsbury, of Newman-street, Oxford-street, Middlesex, engineer, and William Maugham, of Newport-street, Lambeth, Surrey, chemist, for certain improvements in the manufacture of carbonate of soda. Jan. 11; six months.

John Macneill, of Parliament-street, Middlesex, civil engineer, for improvements in making or mending turnpike or common roads, Jan. 11; six months,

James Braby, of Duke-street, Stamford-street, Lambeth, Surrey, wheelwright and coach-maker, for certain improvements in the construction of carriages. Jan. 11; six months.

Robert Sewell, of Carrington, Basford, Nottingham, lace-manufacturer, for certain improvements in the manufacture of white lead. Jan. 11; six months.

Charles Thornton Coathupe, of Wraxhall, Somerset, glass-manufacturer, for certain improvements in the manufacture of certain descriptions of glass. Jan. 11; six months.

John Gall, of Aberdeen, carpenter and builder, for an improved mode of priming fire-arms, applicable to percussion locks. Jan. 17; six months.

Arthur Dunn, of No. 22, Nelson-street, Cityroad, Middlesex, manufacturing chemist, for an improved mode of dissolving silicious matter and

compounds of silica, and of manufacturing soap Jan. 17; six months.

William Gossage, of Stoke Prior, Worcester, chemist, for certain improvements in manufactur ing oxide of lead, applicable to making paints and other purposes; also certain improvements in the process of bleaching and purifying oils suitable for mixing paints and other oils and fatty matters. Jan. 19; six months.

John Murray, of Fitzroy-square, Middlesex, gentleman, for certain improvements in the construction of carriages. Jan. 19; six months.

Moses Poole, of Lincoln's-Inn, Middlesex, gentleman, for certain improvements in ordnance and other fire-arms; being a communication from a foreigner residing abroad. Jan. 19; six months.

Henry Needham Scrope Shrapnell, of Bayswaterterrace, Middlesex, esquire, for certain improvements on snuffers. Jan. 19; six months.

William Stedman Gillett, of Guildford-street, Middlesex, gentleman, for improvements in trimming and facilitating the progress of vessels in water. Jan. 21; six months.

Julius Oliver, of Castle-street, Falcon-square, London, gentleman, for a certain improvement in the filters employed in sugar-refining; being a communication from a foreigner residing abroad. Jan. 24; six months.

Joshua Cuttel, of Hollingforth, near Huddersfield, Yorkshire, woollen-manufacturer, for improvements in producing slubbings of and in spinning wool; being a communication from a foreigner residing abroad. Jan. 26; six months.

LIST OF SCOTCH PATENTS, GRANTED BETWEEN THE 21ST OF DECEMBER, 1836, AND 21sг OF JANUARY, 1837.

John Burns Smith, of Salford, Lancaster, cottonspinner, for certain improvements in the machinery for roving, spinning, and twisting cotton and other fibrous substances. Sealed Dec. 24.

John Roberts, of Prestolle, Prestwick, Lancaster, calico-printer, for certain improvements in the art of block-printing. Dec. 28.

William Neale Clay, of West Bromwich, Stafford, manufacturing chemist, for improvements in the manufacture of sulphate of soda. Dec. 28.

James White, of Lambeth, Surrey, engineer, for certain improvements on railways. Dec. 31.

Baron Henry de Bode, Major-General in the Russian Service, of the Edgeware-road, for improvements in capstans. Dec. 31.

William Sharpe, of Glasgow, merchant, for a certain improvement in the treatment of cotton wool in preparation for manufacturing the same into yarn and thread. Jan. 4, 1837.

William Cooper, glass-merchant and stainedglass-manufacturer, of Picardy-place, Edinburgh, for an improved method of executing ornaments, devices, colours, or stains on glass. Jan. 12.

Hamer Stansfeld, of Leeds, merchant, in consequence of a communication received by him from Christian William Schonherr, of Schneeberg. Saxony, for certain improvements in machinery for weaving, one of which improvements is applicable to other purposes. Jan. 13.

Thomas Vaux, of Wordford-bridge, Wordford, Essex, land-surveyor, for a certain mode of constructing and applying a revolving-harrow for agricultural purposes. Jan. 14,

Charles Thornton Coathupe, of Wraxall, Somerset, glass-manufacturer, for certain improvements in the manufacture of certain descriptions of glass. Jan. 18.

John Ruthven, of Edinburgh, for an improvement in the formation of rails or rods for making railways, and in the method of fixing or joining them. Jan, 20.

NOTES AND NOTICES.

The Patent-office at Washington, in which were deposited models of all the machinery invented (or, at least, patented,) in America during the last fifty years, has just been destroyed by fire, and with it an almost innumerable array of specimens of the ingenuity of Brother Jonathan. Our Transatlantic brethren appear to pay even less attention to precautions against the ravages of fire than ourselves, and we are often culpably remiss in that particular. The present calamity originated in the Post-office, which is described as a wooden building, particuJarly liable to take fire, and the lower parts of which were used as a magazine of fuel. The flames spread from here to the adjacent Patent-office, a building of the same description, and the consequence is, that the records of American invention are swept from the face of the earth,-the immense collection of patent models is entirely destroyed. Amongst them were many, no doubt, whose value was less than nothing; but among them also were some, the loss of which can never be repaired. From paragraphs in some of the recent American papers, it would seem that the fire was the work of an incendiary. However that may be, the Government of the United States have a heavy charge to settle with the inventors of the United States, for keeping the models which the law exacts from them as evidence of their ingenuity, in such a tinder-box as their Patent-office must have been. The American Railroad Journal of the 24th December, which we have just received, after narrating the occurrence, remarks, with respect to the models, drawings, &c. destroyed, "Certainly much useless lumber is removed, for which regret in the slightest degree cannot be felt." With this opinion we must say we perfectly coincide, and so we imagine will our readers, if they have read the abstracts of American specifications given from time to time in the Mechanics' Magazine' -which are only about one in ten of the numberand the best of the lot. We are in hopes of better things from Brother Jonathan under the adminis tration of the new Patent Law.

Death of Professor Farish.-By the death of this gentleman, the University of Cambridge has lost a great ornament, and mechanical science an able cultivator. Since his appointment to the Jacksonian Professorship, he had done much to popularise practical science in the University, and his lectures, we believe, were constantly well attended-they were illustrated by a vast mass of apparatus and models of working machinery. The Professor, it will be recollected, was the chief instrument in the introduction of Isometrical Perspective to general use in this country.

Sir John Soane.- By the death of the venerable Professor of Architecture, it is understood that his house in Lincoln's Inn-fields, and its contents, become vested in the nation. The particulars of this munificent bequest must be fresh in the recollection of the readers of the Mechanics' Magazine.

Steam Carriages on Common Roads.-We understand that Mr. Gurney has built two new steam. carriages-with other people's money, of coursebut that he refuses to run them unless sufficient cash be advanced to build a third, which the moneyparties decline doing. A joint concern of all the steam-carriage patentees has been attempted to be

got together for the purpose of uniting their re sources for the working of the various commonroad steamers. The gentleman who has made the most successful experiments has, however, declined being included in such a junction.

Mails on the Greenwich Railway.-A contract has, it is stated, been entered into between the General Post-office and the London and Greenwich Railway Company, for the conveyance of an "additional" post-office bag, thus conferring on the borough of Greenwich the first-fruits of the new and rapid mode of communication by railways.

Architectural Boards.-In Spain no public building, however insignificant, is allowed to be erected in any provincial town until the design has been submitted to the Academy of St. Ferdinand, at Madrid, which comprises the first architects in the kingdom. The object is to prevent the execution of any deformity at the public expense. In Sweden, a similar law for a similar purpose was introduced by Gustavus the Third, and the Board of Architects, to whom he contided the care of the public.edifices, received and criticised also, if requested, the plan of any important private building, often making improvements, and, in some cases, presenting an entirely new design to the applicant. The German traveller, Eck, declares the consequence to have been a singular and striking elegance in all public and private buildings of note, erected during his reign.

Sugar from Chestnuts.-The manufacture of su gar from chestnuts, says the Bons Sens, will proba bly soon become an object of as much importance as that from beet-root. Some processes of extrac-> tion have already yielded 14 per cent., which is more than equal to the average produce of the beet-root.

"A Friend to Steam-Navigation to In.lia" shall have due attention in our next.

Errata in the Review of the British Museum Report in our last.-Page 292, line 10, for "or Horsfield," read " Dr. Horsfield."

Page 295, line 4, of paragraph 19, after "15 days in the year," read "besides Sundays."

The Supplement to Vol. XXV., containing Ti tle, Table of Contents, Index, and Plate of Specimens of English Medallic Engraving by Mr. Bate was published on the 1st of December, price 6d.

British and Foreign Patents taken out with economy and despatch; Specifications, Dis. claimers, and Amendments, prepared or revised; Caveats entered; and generally every Branch of Patent Business promptly transacted.

A complete list of Patents from the earliest pe riod (15 Car. II. 1675,) to the present time may be examined. Fee 2s. 6d.; Clients, gratis. Patent Agency Office,

Peterborough-court, Fleet-street.

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.

CUNNINGHAM and SALMON, Printers,
Fleet-street.

DESCRIPTION OF THE NEW COINING PRESSES LATELY INTRODUCED INTO THE UNITED STATES MINT, PHILADELPHIA. BY FRANKLIN PEALE, ESQ. (From the Franklin Journal for November.) To the Committee of the Franklin Institute, on Publications.

Gentlemen,-After seven months of experience, it will not be considered premature, to send for publication, a brief notice of the Coining Press, a model of which I had the pleasure to exhibit and describe, at one of the Conversation Meetings at the Institute last year.

This press has been in operation since the 23rd of March, last, the period of the first coinage by steam in the Mint of the United States; and the results, which are more than satisfactory, have authorised us to proceed with the most perfect confidence in the formation of the presses for the branch Mints at New Orleans, and at Charlotte and Dahlonega, in North Carolina and Georgia; also, with the manufacture of others for the use of this Mint, all of which, it is probable, will be completed at an early period in the coming year.

The above design exhibits a side view of the medium-size press, intended to strike eagles, quarter dollars, and cents. Three grades have been adopted, corresponding in linear proportions to the numbers of nine and a half, seven and six, suited to all the denominations of our coin respectively.

The side view (fig. 1.) exhibits the general proportions and arrangements of parts, consisting of a shaft with a fast and loose pulley to receive motion by means of a strap from the moving power, whether water, steam, horse, or hand: the latter, of course, being least desirable, will only be used, when neither of the others is available. Upon this shaft is placed the fly wheel, the momentum of which, during one revolution at the rate of sixty per minute, is found, on trial, to be quite sufficient to overcome the resistance offered by the piece whilst subjected to the pressure of the dies. Upon the same shaft is the crank, which gives motion, through the pitman, to a lever and toggle-joint, the structure of which is exhibited in the left upper corner of the front view presented in figure 2.

The feeding of the blanks, or plan

chets, and their discharge after being struck, is performed by an excentric and set of levers, all combined in so simple a manner, as to be effectual, and not subject to derangement; as much so these parts as are visible in the two views, are faithfully exhibited; but it if impossible to describe them intelligibly without the aid of drawings of the separate parts; and, further, since the drawings were executed, changes have been made in the position and form of the excentric, by which the press is much improved. general notice is all that is intended in the present communication.

The feeding tube is a vertical pipe to receive the blanks, in which they are placed by hand, and from which they are taken by the feeders; the latter are so arranged, that when a crooked, or otherwise faulty blank impedes the motion, (not an unfrequent occurrence in coining,) the whole is immediately released from action, and will not again operate until the impediment be removed.

A few familiar facts are added as evidences of the peculiar adaptation of the toggle-joint to coining, as proved by the operation of the press which is the subject of this notice.

1. The pressure acts with increasing force until the close of the operation, at which time its intensity is greatest, and it is always carried to the same extent.

2. No injury occurs from the absence of a blank from between the dies when the blow is given, an accident that results in the destruction, or great injury, to one, if not both of the dies, in presses of the ordinary construction.

3. An immense saving of labour From trial, we have ascertained that a man, with one hand applied by means of a common winch handle, can coin eighty pieces per minute (the experiment was tried upon cents, which have a diameter of 11 inches). A boy, fourteen years of age, was able to coin sixty per minute, without any unusual exertion; and, lastly, it was impossible for the operator to tell, by the resistance offered to his exertions, whether the pieces were being coined or not.

It is by no means my wish to be considered the first who has applied the toggle-joint to the striking of coin. It is difficult to say to whom priority belongs; for presses on similar principles are in use