journey, upwards of 10 miles an hour. The swiftest travelling was between Tottenham and Waltham, some part of which road was gone over at the rate of nearly 25 miles an hour. Down some

hills was done at greater speed even than this, by mere gravity, the steam being completely shut off, and drags on-which strained the engine nearly as much as the ascent of Wade's Mill-Hill.

This steam journey, although it is one of the worst Mr. Hancock ever performed, will be the most useful to him. It will show him more of the difficulties likely to arise in common road steam traffic, than he has hitherto seen, and he will be enabled the better to avoid them in future, than had they not been experienced. Judging from this trip, it would seem that a greater distance than about 30 miles, should not be performed without either a change of engine, or at least of fire-bars. Lead flange packing should also be avoided, and some substitute for hemp packing devised for the piston-rod and valve-boxes. At Cambridge the cylinders were repacked with copper wire, a most effectual mode. The quantity of coke consumed on the journey was sixty bushels. The tolls paid amounted to 13s. 2d.

Since Mr. Hancock's previous steam travelling, a very considerable change seems to have taken place in the public opinion, as far as it can be judged of from a road-side crowd; instead of the hootings, hisses, and execrations which were bestowed upon him in his previous journies, he was greeted in his progress to Cambridge with applause and blessings and wishes for success.

The matter appears now to be taken up by parties likely to bring steam locomotion on common roads to a practical test, because it is their interest that it should succeed-namely, by the road trustees, inn, and coach proprietors. The Automaton was to remain in Cambridge for a few days, and to journey about the neighbourhood to demonstrate the practicability and advantage of this novel mode of transit. On Tuesday a party of gentlemen of Cambridge were favoured with a trip round Parker's Piece and the neighbourhood, and on Wednesday the Automaton was to make its appearance at the Newmarket race

course.

MODE OF DISCONNECTING PADDLEWHEELS.

Sir,-Perceiving by the Report of Messrs. Pringle and Parkes in your July number, that an easy and rapid means of disconnecting the paddle-wheel of a steam vessel is still a desideratum, I take the liberty of sending you a plan for effecting the same, which, if worthy of notice, you will perhaps do me the favour to insert in your valuable work, of which I am a constant reader. The idea is original with me, but in this inventive age it is highly probable that I have been long since anticipated, and

as

"there is nothing new under the sun," I am quite prepared, for at least a dozen claimants if you should give it your countenance by inserting it in the Mechanics' Magazine.

I remain, Sir,

Your most obedient servant,

JOHN TALLERVEY, Lt. R.N. Westbury on Tyne, Bristol, Aug. 22, 1839.

A A A, paddle shaft, which is to be square excepting at the bearings. B, barrel of paddle-wheel, from which the spokes are to radiate; 1 and 2 circular parts for bearings; this barrel to be square in the inside. C, another square barrel with flanged end, this barrel to fit on to the shaft and into B. DD, two screws, with toothed heads at E E. F, toothed wheel turning on paddle shaft and gearing into EE. GG, two bearings, or supports, attached to paddle shaft for screws D D to turn in; H, a moveable toothed wheel placed under paddle shaft to gear into and turn toothed wheel F; this wheel H to be worked by a winch (should the engine not be stopped at the disconnecting, H would gear into E E, equally well producing same effect.) II, vessel's side for end of screws, DD, to butt against; b b, dotted lines, outline of B, and where it ought to be placed, but for the sake of clearness, all parts are stretched at a distance from each other. There is to be fixed a stopper for checking the wheel when intending to disconnect. The paddle-wheel being checked, and H put in gear and turned by the winch, will of course turn the screws in the holes in the flange of C, which holes, are of course to be tapped or threaded for the purpose, C will be drawn out of B, he ends of

The policy of the mode by which this individual endeavours to patch up the cause of his friends in the north, is excessively shortsighted. He would have us believe that the engines of the Great Western are in a most distressingly dilapidated condition, hardly able to hold together, and with their cylinders and pistons furrowed and injured most deplorably. But what then? These engines in this miserably worn-out condition (according to Piston Rod), were still able to beat the bran-new Glasgow-made ones of the British Queen! If this do not afford proof sufficient of the great inferiority of the Scottish engineers, what will? They could not surely have had a better chance of triumphing over their London competitors than this. According to our veracious informant, the condition of the "chef-d'oeuvre of Maudslay and Field" is now somewhat similar to that of the high-mettled racer when reduced to the sand-cart; and yet (shocking to relate) the crack specimen of Scottish engineering, which he can never sufficiently admire, was left behind out of sight by this cripple, on the third day of their steam race across the Atlantic, and never more had an opportunity of seeing anything of the vessel propelled by the worn-out, ricketty, seriously-injured, but somehow quick-going engines of London manufacture!! Truly judicious is "Piston Rod's" observation that "well it has been said'Save me from my friends!

My other antagonist, "Bowsprit," would be a formidable one, did it not happen that all his facts are fictions. I need only refer to any of the newspapers of 15th and 16th August for proof that, according to the American journals at least, the odds at New York were altogether in favour of the British Queen; and, as to the assertion that "the Great Western reached Bristol only about two hours before the Queen arrived at Portsmouth," I cannot guess the motive for putting such a transparent figment upon record. Any of the journals of the above date will bear witness to the fact that the Great Western arrived early in the morning of the fourteenth of August, and the Queen early in the morning of the fifteenth, the difference being twenty-four hours instead of two, as I thought was known to all the world, until surprised by "Bowsprit's" unaccountable and unfounded assertion to the contrary.

With respect to Mr. Hall, I cannot leave him in better hands than those of " Piston." However, I am tempted to ask him one question. It would refer to what, at first sight, seems a contradiction in certain passages of his two last letters; in one of these (page 404) we are told that "there are injection condensers, as well as his own, on

board the British Queen, that of course the former required blowing-out cocks to be put to the boilers, and that the water" (on the voyage from Greenock to London) was blown out too low by these cocks," from all which it would appear that the injection condensers were in operation on this voyage. Yet the express object of Mr. H.'s former letter (page 252) was to refute the erroneous notion that such had been the case, and on that occasion, in order to set all doubts at rest, Mr. H. observed emphatically "I have been on board during the whole of the passages, and positively assert that not a single stroke of the engines has been made, except by the working of my condensers." What, under these circumstances, becomes of the "blowing out too low" story, by which the injury done to the engines on these self same "excellent passages" is now accounted for? bearing in mind that it is one of the distinguishing excellences of the patent condensers, that the boilers with which they are used never require blowing-out at all!* I remain, Sir, most respectfully yours, OBSERVATOR.

London, Sept. 25, 1839.

COL. MACERONI'S INVENTIONS-MR. HAN-
COCK'S STEAM-CARRIAGES-WOODEN

PAVEMENTS-WATERPROOFING BOOTS-
HALL'S CONDENSERS, &c. &c.

Sir, The extraordinary prostration of body and mind caused by the too sudden dismissal of three ounces of laudanum per day for six years, has prevented me from offering my humble contributions to your valuable pages for many weeks past, save one which I am now sorry to have had the weakness to confer upon Mr. Walter Hancock about his twelve steam-carriages.

There are some little matters in your number of the 14th of this month, which mangre my morbid apathy, I am induced by the clamour of my "friends" to notice. First, there is much said about the " new light on the advantages of wooden pavements, which, for recommending to the lieges of this country in a printed pamphlet, reprinted in the Mechanics' Magazine, in 1825, I was most severely ridiculed in the Monthly Repository of February, 1834 (I think). The first verses of the song which the editor of that clever periodical indicted in praise of my wooden plan, have already

*The boilers being supplied with "blowing-out cocks," put it in the power of any evil disposed person to open them, without there being any necessity for so doing. We need scarcely observe that there is no connexion between the engine and the operation of "blowing out," which, as "Observator" doubtless knows, is a manual operation performed at the discretion of the Engineer.-[ED. M. M.]

"London streets is paved with wood,
Long live Maceroni;

For we'll blow out with summut good,
Saved out of our coal money."

Now, Mr. Editor, all originality about wooden pavements apart, as you have very sagaciously observed in your preface to my Hints to Paviours, the only way to form a firm and even sub-stratum for any pavement, either of stone or wood, suitable to our streets, with so many gas and water pipes, &c., is to be obtained and preserved by my very powerful mechanical flying stone driver, as you named it. Thus, I beg leave to tell all the dupes of the pretended wooden pavement projectors-first, that they have not a shadow of a claim for a patent; secondly, that their wooden blocks will no more keep their level than the stones, without the use of my machine to compress the sub-stratum, and then the blocks. Further, that I shall soon be in a position to contest the point with them, and beat them from the field, covered with ridicule. At any rate, the pages of your excellent Magazine must convince those who read them, that I have far more claim to some of the advantages resulting from improved paving, whether of stone or wood, than any other man existing. But for thirty years I have been "throwing pearls to swine, and preaching to the desert air, on many matters interesting to society!

Another thing I wish to notice, is the very astonishing discussion about "the patent of Mr. Hall" for condensing the steam escaping from the working cylinders and safetyvalves of sea-going steam-vessels, by passing it through a cluster of small copper tubes, all surrounded by cold water, so as to return the fresh water to the boiler, and avoid any incrustation of salt. Now it so happens that in 1825 I assisted in the construction and application of similar condensing fasce of copper tubes, at Mr. Gurney's factory in Albany-street, Regent's-park, which were applied by Messrs. Busk and Keene to three steam-vessels, which were sent to Bordeaux, to navigate the river Garonne, and the adjacent coasts. The fresh water was, and is now, worked over and over again with a very small loss, and may be called distilled water

11

for months, no sea water being used, but that which is requisite to condense the waste steam, by being passed through the drums containing the clusters of copper tubes, which condense the steam.

I should not have spoken of Mr. Hall's "invention," had I not been on the point of making public use of this plan for some steam vessels I am about to build, furnished with my new patent absolute safety and extra powerful boilers.

By the by, I see in your number of the 14th instant, that one of wise men of "The British Association," a Mr. John Isaac Hawkins, illuminates the leiges with a discovery of the advantages of wooden pavements for streets, a subject which you, Mr. Editor, so ably discussed and approved of in remarking on my "Hints to Paviours," so far back as 1825! Moreover, I see in your No. of this day (Sept. 21) that a Frenchman has got the job of rendering hard and dry, the gravel of the Birdcage Walk, and the Parade in St. James's Park, by means of hot coal tar ! Now I did this to Mr. I. R. Pell's garden walks at Blackheath, in 1816. I strongly recommended it in your pages in 1825; and in June 1838, I proposed the operation to Lord Hill, as may be seen in the Naval and Military Gazette of the 7th of July, 1838. In the same letter, I proposed to render waterproof and thrice more durable the boots and shoes of the troops, for sixpence a pair, by means of my simple fusion of tallow and resin, often spoken of in your and other useful periodicals, and so much approved of by your practical intelligent correspondent, Mr. Baddeley. Lord Hill addressed me the following reply:

"Lord Hill has received Colonel Maceroni's proposals, but cannot give him any employment.

"Horse Guards, July 18, 1833."

Now a Frenchman is employed on the very same thing that I have practised and preached ever since 1816! I shall soon publish two other volumes of my memoirs, when it will be seen what numerous robberies have been perpetrated on my brains, both by private and public parties, in military and scientific inventions, or suggestions.

Amongst other piratical robberies I have suffered, is that of my waterproof percussion lock for artillery, the model of which I have left at your office, and should have long since have demonstrated to you, and assisted in its exhibition to your scientific readers, had not a rare combination of ill health, and other" untoward" circumstances caused delay and desperation.

In 1830, you published in your excellent journal my ideas on the identity of electricity, galvanism, magnetism and solar light;

In

two years after a man starts up, and strong in patronage and in place, proclaims and gets the credit of "his discovery"! 1826 I published in your journal my plan of using a combination of coal tar and whale oil with small coal, or cinders for the use of steam ships, as producing more heat in less compass, than common coal or wood. Now, the very government have adopted this fuel, recently "invented" by somebody else!

Whatever merit or demerit may be due to Captain Ericcson's screw propeller for ateam vessels, I have Admiral Sir Edward Owen's letters to show that I presented the models of the same thing in the year 1828.

In 1824, I presented to the Admiralty my plan of steam ships, shot proof at the bows, and a bulwark 8 feet high, armed with one or two guns to project horizontally 12 inch shells. At 1,000 yards not one shot in a hundred fired from a line-of-battle-ship, would hit the sharp prow of such a steamer, and all that did, would glance off without doing any harm to ship or crew, or pad 'le wheels. But the great broadside of the liner offers a vast and sure mark for the 12 inch shells, and above 20,000 square feet of canvas and tarred ropes, masts, yards, &c., for volleys of fifty of my prehensible naval rockets every minute. Now, they are arming war steamers with large bomb cannon; but we shall see what they will do against my rockets, which the late Sir Thomas Hardy, Sir W. S. Pechel, M.P., and other naval authorities have declared, "must put an end to all ships rigged in the present mode."

But it would be endless to enumerate all the labours that have been substantially successful, although fruitless as to profit to, Sir, your obedient servant,

MACERONI.

RECENT AMERICAN PATENTS. [Selected from the Franklin Journal.] STEAM ENGINES, Nathaniel Bosworth, Philadelphia, July 9.-The patentee says: My first improvement consists in the manner in which I construct and set the boiler or boilers, and connect them with the pipes for the conveyance of steam, and the auxiliary parts of the engine. The boilers which I employ are of the cylindrical kind, and they are to be so set that they may be completely surrounded by the flame and heated air from the fire, and have their whole sur

face, therefore, converted into a fine surface, instead of exposing one-half only of the boiler to the direct action of heat, as is usually the case. These boilers, as they are to be entirely surrounded by the fire, are to be kept completely full of water, and are not subject, therefore, to burn out. They are to be so set as to form a considerable angle with the horizon, rising from their front towards their back ends about one inch in a foot, by which elevation the steam will be caused to escape readily from the boiler into the steam-chamber or receiver at its upper end."

"The steam-cylinder, with its stuffingbox and piston, has nothing in it peculiar, excepting the construction of the piston, which is made of metal, in one piece, and without packing; it may be formed of hard cast-iron or of cast-steel, and must be finished perfectly true and smooth. Its diameter is to be such that when its temperature is raised one hundred degrees above that of the cylinder, it will still pass through it readily, but leaving no sensible space between the two. When of the same temperature with the cylinder, it will of course pass through it loosely. Up to a diameter of four inches, I think it best to have the piston perfectly solid; but if above this size, it may be hollow for the purpose of decreasing its weight.

"Such a piston I have found to work without any apparent friction, beyond that which necessarily exists in the passing of the piston-rod through the stuffing-box; and the most careful observation leads to the conclusion, that there is not any loss of steam between the piston and the cylinder, and if there is any, it has been practically proved to be so small in quantity as to be more than counterbalanced by the decreased friction, and by the other advantages resulting from the improved construction of the engine." The valve is constructed with reference to a peculiar proportion of its parts, which is illustrated by a diagram; in its general construction it is nearly like some others; its peculiarities we cannot conveniently discuss in the space allotted to our animadversions. It is calculated to cut off at such part of the stroke as may be required.

To indicate the quantity of water in the boiler, a glass tube is used, as in some other machines, its upper end being connected by a pipe, with the steam chamber, and its lower end with the lower part of the boiler. It is placed at a distance of six feet from the boiler, and from this circumstance, and the arrangement and construction of the tubes, it will always remain cool, whilst it may be so situated as to secure it from the liability to be broken by accident.

"In my improvements, I have had in