which is strikingly elementary, both in point of information and experiments; and yet his observations never appear as being commonplace, for it is perceived that they are always pointing at-what in the end they never fail of conducting us-the most refined and discriminative investigations.

In explanation of the increased illuminating power of the lamp, Mr. Faraday exhibited the scintillating and highly luminous appearance of charcoal when burned in oxygen gas, and showed that the effect is due to the highly ignited or incandescent state of the particles of carbon, and not simply to their combustion. This fact he confirmed, by projecting into a gas flame magnesia powder, which being incombustible, the greater illuminating power of the flame, which was produced could not be caused by the combustion, but merely by the ignition of the particles of the powder. So in regard to the argand burner, the volatilized carbon of the oil is brought by means of the oxygen gas to an intense state of ignition, and thus a greater quantity of light is produced, without an increase in the consumption of oil. Other experiments were introduced in further elucidation of this fact, and such as showed the unignited condition of carbon in the body of flame; but the proposed application of the invention, as being a matter of great importance, requires now to be noticed.

It appears that the system in which the French light-houses are established, of having lenses instead of reflectors, has its advantages; but these cannot be properly developed without a most intense central light, but in which the height of the flame is not a matter of consequence, or rather, is undesirable. It also appears that it would be of vast importance to have the power of increasing this light according to circumstances. Fresnel's lamp of concentric wick does not fulfil these conditions, besides which, the expenditure of oil is very great in proportion to the light produced. But the oxy-oil lamp fully answers these purposes. At the same instant that the flame becomes more brilliant by the admission of oxygen gas, it shortens in its length, whilst within certain limits its quantity and intensity can be varied at pleasure. The arrangement proposed for a light-house is, to have a number of hollow or argand wicks, of about half an inch in diameter, placed in a circle of about six inches in diameter. each wick may thus be trimmed separately without interfering with the general light, ; and, of course, only a portion of these need be burned, if thought sufficient for the occasion. Such a light was introduced in the lecture, and its power of illumination was

399

indeed astonishing. We could have wished to have seen it in juxta-position with an oxy-hydrogen light, and under circumstances suitable for instituting a comparison. We understand that there is some probability of this invention being applied to the lighting of the House of Commons.

In regard to economy, it remains to be observed that, as the ordinary light is augmented two and a half times for a given quantity of oil, one and a half times that quantity is saved, the cost of which at 68. 8d. per gallon, will nearly cover the expense of the oxygen gas. Allowing for the wear and tear of the apparatus, the interest of capital, and other items, the cost of the gas may be stated as being twice that of the oil. It appears that one pint of oil will require ten cubic feet of oxygen gas, and give a light in one hour equal to thirty-seven argands, the cost of which being Ten pence for the oil and twenty pence s. d. for the gas, will be..... 2 6

In the ordinary mode of burning oil it
would take two pints and a half to
produce the same effect..
By Fresnel's lamp of concentric wicks
there would be required four pints

and a half of oil...

. . . . . . . .

2 1

3 9

The light, therefore, is but little more expensive than ordinary oil-light; but cost, in the case of light-houses, is but a minor consideration when put in comparison with increased efficiency in answering their important purposes.

Mr. Faraday, in the course of his lecture, made some very just remarks-elicited by the originality of this invention being questioned as due to Mr. Gurney-on the little estimation in which mere suggestions, although claiming priority, should be held in comparison with the talent and energy required to overcome the difficulties which are ever consequent on all attempts to carry them into practice.

If we may subjoin a remark of our own on the utility of this invention, we would observe that the superiority of effect appears to us to be attainable only by means that are too elaborate, and involving too much manipulation. The additional supply of oxygen may be obtained more directly and more readily from the atmosphere by an extension of the ordinary means by which combustion produces a draught or current of air; and even should it be necessary to resort to mechanical means to procure the strength of current required, as in Mr. Beale's patent lamps, still it would be a simpler method than the chemical process, and one less liable to failures. then oxygen supplied in this form is diluted with so large a proportion of nitrogen, that the additional aid to combustion, or rather,

But

in the case of oil, to a higher state of ignition, is completely neutralized by the cooling effect of the current, so that the argand oillamps already afford, by means of the ordinary draught of air, the maximum of illuminative power. This, however, is not the case with the more volatile oils, for here the mass of free volatilized carbon is so dense, that on being more abundantly supplied with oxygen, the combustion and heat become so intense as not to be quelled by the accompanying nitrogen, and thus the particles of carbon are raised to a more luminous state of incandescence. Hence it is that the naptha lamps require, and will bear so strong a draught, and that they produce so white and brilliant a flame, equal, in our opinion, to the oxy-oil flame in intensity, though not in height. Hence also it is, that in the combustion of still coarser materials Mr. Beale employs a yet stronger current of air (mechanically produced) with so excellent an effect. The combustion of the volatile oils may, in the case of light houses, be very easily aided, if need be, by a chimney; but whether this mode would be equal in efficiency to the oxy-oil light; besides being, as it undeniably would be, superior to it in point of cheapness and simplicity, is a question that can be determined only by experiment.

LIST OF SCOTCH PATENTS GRANTED BETWEEN THE 22nd JANUARY, AND THE 22nd FEBRUARY, 1839.

Edward Cooper, of Piccadilly, Middlesex, stationer, in consequence of a communication made to him by a certain foreigner residing abroad, for improvements in the manufacture of paper. Sealed Jan. 23, 1839; four months to specify.

Peter Taylor, of Birchen Bower, within Chadderton, Lancaster, rope maker, and slate merchant, for improvements in machinery for propelling vessels, carriages and machinery, parts of which improvements are applicable to the raising of water. Jan. 23.

Frederick Cayley Worsley, of Holywell-street, Westminster, Middlesex, Esq., for certain improvements in locomotive engines and carriages. Jan. 24.

Thomas Walker, of Birmingham, Warwick, clockmaker, for improvements in steam-engines, which improvements are also applicable to the raising or forcing fluids. Jan. 24.

Thomas Sweetapple, of Catteshall Mill, Godalming, Surrey, paper-maker, for an improveinent or improvements in the machinery for making paper.

Jan. 28.

John Wilson, of Liverpool, Lancaster, Lecturer on Chemistry, for certain improvements in the process of manufacturing alkali from common salt. Jan. 30. Sally Thompson, of North-place, Gray's Inn Road, Middlesex, for certain additions to locks or fastenings for doors of buildings, and of cabinets, and for drawers, chests, and other receptacles for the purpose of affording greater security against

intrusion, by means of keys improperly obtained. Jan. 31.

Job Cutler, of Lady-Pool-lane, Birmingham, Warwick, and Thomas Gregory Hancock, of Princess-street, machinist, for an improved method of condensing the steam in steam-engines, and supplying their boilers with the water thereby formed. Jan. 31.

Horace Corey, of Narrow-street, Limehouse, Middlesex, batchelor of medicine, for improvements in the manufacture of white lead. Feb. 7.

Edward Tamwell, of Liverpool, merchant, for improvements in the manufacture of soda. Feb. 7.

Timothy Burstall, of Leith, Scotland, engineer, for certain improvements in the steam-engine, and in apparatus to be used therewith, or with any other construction of the steam-engine, or any other motive power for the more smooth and easy conveyance of goods and passengers on land and water, part of which will be applicable to water power. Feb. 11.

Charles Gabriel Baron de Suaree, of Red Lionsquare, Middlesex, Colonel in the French service, and William Pontifex, of Shoe-lane, London, coppersmith, for a new mode of obtaining vegetable extracts. Feb. 12.

Morton Balmanno, of Queen-street, Cheapside, London, merchant, for a new and improved method of making and manufacturing paper, pasteboards, felt, and tissues, communicated by a foreigner residing abroad. Feb. 14.

Joseph Birch, of Bankside, Blackfriars, Surrey, calico printer and designer, for certain improveinents in printing cotton, woollen paper, and other fabrics and materials. Feb. 19.

Harrison Grey Dyer, of Cavendish-square, gent., and John Hemming, gentleman, of Edward-street, Cavendish-square, Middlesex, for improvements in the manufacture of carbonate of soda. Feb. 19.

Edward Rearson Tee, of Barnsley, York, dyer and linen manufacturer, for improvements in weaving linen and other fabrics. Feb. 20.

Joseph Bunnett, of Deptford, Kent, for improvements in steam-engines. Feb. 20.

NOTES AND NOTICES.

Patent Inflated Saddles.-Sir, I have been informed of a paragraph being inserted in your Magazine, No. 809, for Feb. 9, stating that a new invented, air-seat saddle, by a Mr. Collinson of Burneston, was about to be made known to the public. Being the patentee of the inflated air-seat saddles, I consider Mr. Collinson's to be an infringement; my claim and legal right being to all saddles of that kind as the first inventor. The patent inflated saddle has been in use and on sale for three years past. Thomas Taylor, Banbury.-Feb. 23, 139.

Improvement in Woolcombing.-A very important invention in the woollen manufacture has lately been patented in Great Britain-it consists in heating the carding engines and combs by steam, which has the beneficial effect of allowing the wool to be stretched or extended as it is operated on by the teeth of the cards or combs, without breaking the fibre. By the use of the process, out of every 100 pounds of undressed wool, 95 of the best wool may be obtained; whilst by the methods now in use 65 pounds is the best result. The invention is of French origin, and so great are the advantages considered to be, both in point of quantity and quality, that until machinery can be got ready here, engagements have been made to send wool over to France to be combed, and then to be returned to England; and which it has been calculated will render a good profit, notwithstanding a duty of 40 per cent. upon its importation.

LIEUTENANTHALL'S PATENT OBLIQUE

PADDLE-WHEELS.

The objects of this invention of Lieut. Hall, R.N., are those usually proposed in improved paddle-wheels, viz:-The removal of the distressing and injurious tremor in steam-vessels, occasioned by the stroke of the paddle-boards upon the water; the avoidance of the lift of back-water; and the employment of the powers of the engine to the greatest possible advantage. In Lieutenant Hall's wheel the arms or spokes diverging from each extremity of the shaft, are not opposite and parallel to each other respectively, as in the ordinary wheel, but those at one end are placed alternately with respect to those at the other end of the shaft. The paddle-boards uniting these arms are consequently at an angle with the axis of the wheel. They are also joined together so as to form angles with each other throughout their entire breadth, and salient and re-entering angles with the side of the vessel. The paddle-boards are made to assume the requisite form by being slightly twisted, from right to left and left to right alternately, which is readily effected by previously steaming them; and they are sufficiently rounded to preserve an equal dip in the water in all dispositions of the wheel. There is thus obtained a continuous surface representing a single paddle-board, carried in alternate directions from arm to arm round the wheel until the extremities meet.

The paddles are affixed to each wheel, so that the salient angles of the one wheel shall enter the water at the same instant with the salient angles of the other, and, as necessarily follows, the re-entering angles of each wheel also enter simultaneously. The resistance is then identical with that of oars when rowing, with the advantage of being continuous. By this coincidence of the entry and exit of the corresponding boards on both paddles, that lateral motion to which the paddleshaft would be liable in its bearings, were this not attended to, is prevented.

In action, the paddle-boards thus arranged enter the water in an endless series, and increment by increment, without noise or any concussion upon the water, and present to it, throughout the entire revolution of the wheel, an equal and constant resistance; while the action

upon the water is at right angles with the shaft or line of motion.

The results of this construction are stated by the inventor to be the accomplishment of the before stated objects:perfect freedom from all vibration communicated to the vessel by the paddlesabsence of any disagreeable noise or flapping of the paddles upon the water— no lift of back-water by the emerging paddles-the greatest regularity and smoothness in the action of the engineincreased speed imparted to the vessel, (beyond that hitherto obtained with equal power,) by the avoidance of the lift of back-water and the application of a continuous propelling power in place of the alternating or reciprocating one heretofore employed.

When the vessel is laden beyond her ordinary trim, or where it may be deemed desirable to employ deeply immersed wheels, the advantages derivable from this construction are proportionally augmented.

Although the expression, "paddleboards," has been exclusively used in the above description, iron or other metal may be substituted for wood. The construction partakes of the properties of consecutive arches resting alternately upon each other, and consequently presents the strongest form of which divided parts are susceptible. Simplicity is also a prominent characteristic of these wheels, and, as regards expense, they do not exceed that of the most ordinary paddle-wheels in present use.

Description of the Figures.-Fig. 1 is a front view of the wheel, its axis being a little below the level of the eye; and fig. 2 an edge view of the same wheel. The same letters indicate similar parts in each figure wherever they occur.

АА,

the shaft or axis; BB, the arms nearest the eye; CC, the arms diverging from the distant end of the shaft; DD, the bosses; EE, the exterior ring nearest the eye; FF, the exterior distant ring. The figures on the float-boards indicate the manner in which they follow each other in consecutive order, without any opening or space between them—each being supported by that which precedes and follows it throughout the entire circumference of the wheel.

Fig. 3 differs from Figs. 1 and 2, in having two sets of float-boards, but they are set on in precisely the same manner

as those in Figs. 1 and 2, and are marked with the same letters of reference. This arrangement is to be preferred when the breadth of the wheel is such as to render three arms requisite to support each paddle on the ordinary construction.

Models of these wheels having been submitted to the Government authorities, the Lords of the Admiralty were pleased to order a trial to be made of their merits by their Chief Engineer and Inspector of Machinery. Paddles of the required form were consequently constructed at Woolwich Dock-yard, and temporarily attached to the previously-existing frame-work of the Dasher, a new steamer just fitted out for the packet service. The official Report made to their Lordships, of which they were pleased to inform the inventor by Sir John Barrow's letters of the 5th of March and 4th of May last, was, that the results of the trial were favourable and satisfactory.

These wheels have been since permanently fitted to a steam-boat of fiftyhorse power at Liverpool, and have been in constant daily service between Woodside and Liverpool, or in towing heavy vessels out of the harbour, for upwards of three months, and during unusually severe weather.

From amongst a number of most satisfactory testimonials which we have

seen, we select the following by Captain Denham, as being the most comprehensive, and coming from the best autho rity.

"Marine Surveyor's Office, Liverpool, November 22, 1838.

"My Dear Sir,-According to my promise, when your diagonal floats were fitting at this port to the Helensburgh steamer, I have taken the opportunity of trying their comparative effects with those of the ordinary water entrance and exit, and I am satisfied that you have completely obviated that disagreeable and bolt-loosening tremor common to steamers, and promoted the impetus in proportion as you avoid the usual lift of back-water. These advantages resulting from no additional expense must carry an adoption wherever known. In the Helensburgh's cabin I experienced no more vibration than in a sailing vessel; nor on the paddle-box could a drop of water be detached by agitation from the convex surface of a brimful tumbler; whilst at night you could steal along an enemy's shore, or into his fleet, without imparting any of the telltale flapping of the usual paddle-float. Most heartily wishing it the early general adoption it deserves.