From the account of the proceedings of the Section, published in the Athenæum, it appears, that after my letter, in which the facts above-mentioned were stated, was read, a Mr. Maugham, who is employed to exhibit the hydro-oxygen microscope at the Adelaide Gallery, London, asserted that I had accomplished the fusion, of which mention has been above made, by means of a blowpipe of his contrivance, which I had purchased while in London.

The opinion which I am obliged to entertain of an individual capable of this groundless assertion, would cause me to consider him unworthy of notice, had not his mis-statement been made before an assemblage which I most highly esteem, and had he not been honoured by a premium for his pretended invention by a respectable British Society.

The blowpipe which is thus falsely alleged to have been used by me, differs immaterially from one of which I published an engraving and description in the American Journal of Science for 1820, vol. ii. p. 298, being a modification of that originally contrived by me and republished in Tilloch's Philosophical Magazine, vol. xiv. for 1802.

Between the instruments described in these publications, or in the Franklin Journal, and that employed by Maugham, the only difference worthy of notice is, that the latter is near the apex bent so as to form an acute angle, and is thus rendered suitable for directing the flame upon a revolving cylinder of lime.

Although I purchased of Newman a blowpipe bent as described, with an apparatus attached for holding and turning a cylinder of lime, I have never made any use of it, having for the purpose of subjecting lime to the flame, found my modification above referred to, as described in this Journal, preferable. It only required the jetpipe to be directed upwards in an angle of about forty-five degrees with the axis of the lime cylinder.

I do not consider the form of my blowpipe employed by Mr. M. as qualified for the fusion of any metal.

It is remarkable that an apparatus of gasometers, employed by Maugham, at the Adelaide Gallery for the supply of the gases for the blowpipe, differs but little from the apparatus proposed for the same purpose in my communication above adverted to, and published nearly twenty years ago.

However, the process by which I have

lately extended the power of the hydrooxygen blowpipe may differ from those to which I had previously resorted, it differs still more from that modification which Maugham has claimed as his own.

NOTES AND NOTICES.

Packer's Pole Lathe Chuck.-Sir,-In my late communication, one thing essential to its success has been overlooked, namely-the mode of supplying it (the pole-lathe chuck,) with oil. The following is the plan that suggested itself to me:Drill a small hole through the centre of one of the brass pins, and counter-sink both ends; introduce into the said hole, an iron pin, with a head very similar to that of a common iron screw; even a screw itself might be preferable. However, either may be used at discretion. This pin will form a valve, and one for each groove will suffice. I am, Sir, yours respectfully, R. L. PACKER.

- Penny Postage.-Several highly respectable firms in London, have resolved--and announced their determination by public advertisement, not to send or 1eceive any post letters that are not pre-paid; prepayment of which will be greatly facilitated by the promised issue of stamp, stamped paper and envelopes, by the use of which every person will be effectually protected against the forgetfulness or dishonesty of his servants. The policy of such a measure seems so self-evident, that it is probable it will very shortly become a universal rule, “ a consummation most devoutedly to be wished." This regulation seems indeed to be part and parcel of the Penny Postage system-in fact, its very essence, non payment being treated as a sort of misdemeanour and visited with fines. Government are entitled to the gratitude of every true friend of his species for this inestimable boon, which renders friendly or commercial intercourse almost "free as the air we breathe;" and they richly deserve the most cordial co-operation, in carrying out their plans, by all who are participants in this national blessing. W. B.

Beetroot Bread.-A very important discovery is spoken of in Paris among scientific men; a gentleman has succeeded in making very excellent bread from beetroot, mixed with a small portion of potatoflour. It is said that this bread is of a very excellent quality, and can be sold to the public at so low a price as two sous per pound.

Calico Printing in Naples.-An eminent en-. graver to calico printers in Manchester is now executing 38 engraved copper rollers (9 8ths wide) for a calico printer in Naples. Messrs. M'Farlane and Briggs are making a three-coloured machine for the same parties.-Preston Observer.

Exportation of Iron Steamers.-A Liverpool ship brought to Boston, U. S., a whole iron steamer, the other day, in sections. The length is 160 feet, I believe! They have just launched a much larger one at Pittsburg.—Athenæum.

At St. Louis they talk strongly of a wire suspension bridge over the Mississippi, and the city has appropriated money for the purpose.--Ibid.

Cochrane's many-chambered Rifles and Ordnance. -Mr. C. is now making a six-pounder for Mehemet Ali! He made a twelve pounder for the Sultan, at Constantinople, in 1835, which gives eight discharges a minute, and has no recoil.-Ibid.

ERICSSON'S IMPROVED STEAM

ENGINE.

[Patent dated July 6, 1839; Specification inrolled January 5, 1840.]

This new steam-engine is intended particularly for locomotive carriages and steam navigation. It consists (as applied to locomotives) in two radial pistons performing partial rotary and reciprocating movements within two half cylindrical chambers placed horizontally and transversely on the carriage, and being attached to each other, the axes or shafts to which the said pistons are fixed (and which form their centre of motion) being made to pass through stuffing boxes in the covers of the said half cylinders, and extending in opposite directions beyond the outside frame of the carriage, the ends of these shafts being provided with crank levers, which, by means of connecting rods and pins, are connected to circular discs or cranks, fixed on the outer ends of the axis of the driving wheels. And, as applied particularly to steam navigation (that is, for giving motion to the ordinary paddlewheels, or to any rotary stern propellers) the engine consists of similar radial piston axes, levers, and connecting rods, performing similar reciprocating and partial rotary movements, and working within half cylinders placed either transversely or longitudinally in the vessel, and attached to each other.

Three modifications or arrangements of this engine are described in the specification: the first, as applied to a locomotive; the second, as applied to a steam vessel to work paddle-wheels at the sides of the vessel; and the third, as applied to the working of any kind of stern propeller. This last arrangement, as being the most novel and beautiful, and as comprehending the others, we think will be quite sufficient to give our readers a clear idea of the invention. The figure on our front page is a transverse section of a steam vessel, with a front view of Capt. E.'s improved engine.

In order more clearly to exhibit the various parts, it will be seen that the exterior view of one half of the engine is shown, whilst the other half is shown in section; A and B are two half cylinders, provided with flanges, which are attached to cast iron frames, CC, these frames being divided at c c, each half serving the purpose of end cover to the cylinders,

and firmly bolted together at cc. These frames or end covers C C are firmly bolted to timbers placed longitudinally at the bottom of the vessel; D and E are the piston shafts to which the radial vibrating pistons before mentioned are attached; e being the piston attached to the shaft E; a a are plummer blocks or bearings in the frames CC, for carrying the piston shafts, and kk are keys for adjusting these bearings; F F are the top covers o the cylinders, and f is one of the metallic rods for preventing any escape of steam round the shaft; G is a double-acting air pump, constructed upon the same principle as the steam cylinders with a similar vibrating radial piston as shown by dotted lines on the drawing; H is a condenser, with a rose jet h, similar to those used in common condensing engines; I is the suction valve, and i the valve communicating to the hot-well J; g is a crank lever attached to the piston shaft of the air pump, and d is another crank lever attached to the end of the piston shaft D. These crank levers give motion to the piston of the air pump by means of a connecting rod K;

are the steam passages, and L the eduction valve, by which the steam is alternately let into the condenser. This valve, as well as the induction valve, is worked by ordinary gear communicating with the main shaft. The steam passages communicating between the induction valve and the cylinder, are placed behind the passages 1, 1, and similarly constructed, as will be seen in figure 5, the induction valve itself may be constructed either upon the principle of the ordinary slide valve, or like the eduction valve, L, M, and N, (shown by dotted lines) are crank levers fixed to the ends of the piston shafts. The extent of the motion of these crank levers is marked by plain lines. O is the main shaft of the engine, and the continuation thereof is a paddle shaft, which passes through the stern of the vessel for the purpose of giving motion to either a wheel constructed with spiral plates, or to a screw, or to any other rotary propeller. RR are brass bearings fitted into the lower part of the frame C C for carrying the main shaft O; r, r, are the caps for securing the said brass bearings; S is a circular plate of iron firmly attached to the main shaft; S is a double crank pin fixed in this circular plate, and which pin, by

at the bottom of the cylinder,which then burns like an ordinary gas light, and like it, would blacken the surface of any cold body presented to it. The wire cloths, if not broken through by violence, will last for months, although in daily use, and if covered by a layer of coarse sand, or pounded limestone will continue serviceable for an unlimited period.

When more intense heat is required than is attainable by the unaided combustion of the mixed gases, recourse may be had to various forms of blow pipes; and when a large volume of such flame is to be employed, the current of atmospheric air may be urged by double bellows. A very efficient apparatus on this principle is to be seen in the laboratory of Dr. D. B. Reid.

It is to be regretted that such applications of gas are not more generally known and introduced into workshops, as there are numerous processes in the arts in which they would afford facilities to the workman which he can scarcely command by any other means; for example, in the hardening of steel tools, it is well known that a piece of bright steel when heated to redness in a forge, or muffle, is subject to oxidation, and that a black scale remains after hardening, which it is difficult to remove without some injury to the work, as in the case of a screw tap; whereas, if the same piece of steel be heated in a flame of the mixed gases, where there is no free oxygen to attack its surface, it may be made and kept red-hot without any injury to its finest edge; it will be discoloured, but without losing much of its polish. The artist has also the advantage of a distinct view of the article while it is being heated, and the power of withdrawing it from the flame the moment it has acquired the proper colour, which in the hardening of cast-steel cutting tools is of great importance.

Many attempts have been made to apply carburetted hydrogen and pure hydrogen gases to the purpose of warming buildings, and a variety of forms of stoves have been proposed, on the understanding, it would appear, that, by applying the flame of the gas to metallic bodies, an increased degree of heat would be communicated by them to the atmosphere around them; a little consideration will show, that however the distribution of the heat may be modified

by such contrivances, there can be no increase of the heating power; and that when a certain measure of gas is fairly burned, the heat evolved into the apartment will be the same whether the flame be disposed as a light, or made to play against metallic plates, or other combinations of apparatus. In all cases where the products of the combustion are allowed to mix with the atmosphere of the apartment, without provision being made for carrying them off by ventilation the effects of such processes must be more or less deleterious to health according to the proportion these products bear to the mass of air they mix in.

On the whole, it may be assumed that this mode of heating apartments is the most expensive, the least efficient, and, excepting that by Joyce's charcoal stove, the most insalubrious that can be resorted to.