INVENTION OF PHOTOGENIC DRAWING.

[From the Athenæum.]

During the discussions which took place in Paris respecting the priority of the discovery of M. Daguerre and Mr. Talbot, the name of M. Niepce was incidentally mentioned as the person to whom the former was indebted for the first idea of fixing the images represented in a camera obscura. Subsequently, M. Niepce's claim to honour has been more fully admitted; and this has been singularly confirmed by Mr. Bauer, in a letter published in the Literary Gazette. Mr. Bauer therein states. that, in 1827, he became acquainted with M. Niepce, then on a visit to his brother at Kew; that M. Niepce made known to him, and others, that he had discovered a means of "fixing, permanently, the image of any object by the spontaneous action of light," and exhibited several specimens. That, by the advice of Mr. Bauer, he, M. Niepce, drew up a memoir on the subject, dated 8th December, 1827, which he forwarded to the Royal Society, but which was subsequently returned, because it is contrary to the rules of the Society to read a paper referring to a process which is not disclosed. That shortly after, and when about to return to France, M. Niepce presented Mr. Bauer with specimens of the newly-discovered art, which are now in his possession. Thus, then, the question of priority, as between England and France, is settled beyond all dispute* at the same time, we must observe, that the processes of M. Daguerre and Mr. Talbot are manifestly different. As to the relative merit of M. Niepce and M. Daguerre, there is no doubt, in our opinion, that, though the first idea was suggested, and the earlier specimens produced by M. Niepce, yet that he was long and zealously assisted by M. Daguerre, who had been for many years engaged in similar pursuits; and there is legal proof that, so early as 1829, they entered into an agreement, by which they declare themselves" associés pour exploiter le pro

first, supposed to be the chlorure of silver, known to be susceptible of change from the effect of light; but on this substance light produces shade, and vice versa, nor is the effect permanent. On M. Daguerre's composition, on the contrary, dark spots produce corresponding shade, and that in every gradation of tint. The moon's ray had no effect on the chlorure of silver; it has on M. Daguerre's composition, and reproduces its own image perfectly."-E. S.

*Not so. The Editor of the Athenæum and these other claimants to the invention of photogenic drawing, appear to have overlooked the claim made by Sir Anthony Carlisle for himself and Mr. Wedgwood, as having performed experiments upon the subject 40 years ago, many years prior to the dates of the evidence of the earliest of these new claimants. We refer our readers to Sir Anthony's letter, No. 809, p. 329.-ED. M. M.

429

cédé à l'invention duquel ils avaient concurru l'un et l'autre." Mr. Bauer is, indeed, in error, when he states that the specimens presented to him, in 1827, by M. Niepce, are quite as perfect as those produced by M. Daguerre, and described in the French papers in 1839. The specimens in the possession of Mr. Bauer, and others, given at the time to Mr. Cussels, of Richmond, have been obligingly'submitted to our examination. They may be divided into-pictures copied from engravings, and pictures copied from nature. The best specimens of a copy from an engraving belongs to Mr. Cussels; and, though somewhat different in its style and general effects, it is not, considering that it has been exposed for more than twelve years to all the casualties of dust and damp, much inferior to similar copies shown to us, when lately in Paris, by M. Daguerre. Mr. Bauer possesses the only copy of a picture taken from nature; but this, so far from being equal to the specimens produced by M. Daguerre in 1839, is even more shadowy and indistinct than any of the earlier specimens of the art which we saw in Paris, and immeasurably inferior to the latter works. That the early process of M. Niepce, and the present one of M. Daguerre, are essentially the same, though greatly improved, we cannot doubt, As M. Daguerre has good and sufficient reason for not making his secret known for the present, the pictures exhibited by him are covered to the very edge with paper; notwithstanding which, we came to the conclusion that the material was either pewter highly polished, or washed with silver; and all the specimens in the possession of Mr. Bauer and Mr. Cussels are on pewter, apparently covered with a very thin coating of transparent varnish; but whether this varnish was applied before receiving the impressions, or subsequently, to fix them, is not obvious: we incline to the latter opinion. The most curious fact, in relation to this discovery, yet remains to be told. It would appear, considering the character of the pictures, all but impossible that impressions from them could be multiplied after the manner of an engraving; M. Daguerre, indeed, stated to us that it was impossible, and it is but reasonable to believe that he is as fully informed of the nature and extent of the discoveries as M. Niepce himself. Yet, in 1827, M. Niepce not only declared that it was possible, but produced specimens of such multiplied copies and Mr. Bauer has now in his possession, not only copies of engravings, fixed permanently by the action of light, not only scenes from nature, but metallic plates engraved, and engravings copied from them: and he understood and

:

believes that no engraving tool was used, but that the drawings were fixed by the action of light, and the plates subsequently engraved by a chemical process, discovered by M. Niepce. If so, the greatest secret of all remains yet to be made public, and is, we believe, as unknown to M. Daguerre as to others.

ERICSSON'S STEAM-BOAT PROPELLER. The experimental iron steam-boat Robert F. Stockton, constructed for testing Capt. Ericsson's propeller, which we noticed some time since, being on the eve of departure for the United States, at the request of a number of scientific gentlemen who were desirous of witnessing her performance, the proprietor consented to another trial being made, and on Saturday last a large party was invited for this purpose. Among those present were MajorGeneral Sir John Burgoyne, Chairman of the Board of Public Works, and Commissioner for Steam Navigation, &c., in Ireland; Major Robe, of the Royal Engineers; Mr. James Terry, of Dublin, largely concerned in canal navigation; Messrs. Vignoles, Delafield, Reid, Napier, and Thomas; several distinguished Swedish naval officers; Captain Stockton, of the United States navy; Mr. Ogden, Consul of the United States at Liverpool; Mr. Young, an American civil engineer, &c. Some 30 gentlemen were present, and the result of the trial gave universal satisfaction.

One of our correspondents having before described the construction of the new propeller, we will now more particularly direct attention to the effect produced during the trial, which appeared quite conclusive as to the success of this important improvement in steam navigation. The distance from the West India South-dock to a point opposite Woolwich church and back, measuring 37,000 feet, was passed in 45 minutes precisely (21 minutes with, and 24 against the tide), the boat towing at the time a heavy city barge on the one side, a large wherry on the other, and another wherry astern. The speed of the engine being repeatedly timed by one of the gentlemen present, Mr. Young, an intelligent American engineer, it was found to average 66 revolutions per minute, or 2,970 during the 45 minutes. The inventor demonstrated, by accurate working drawings, that the spiral planes of the propeller are set at such an angle, that had the resistance of the water been perfect, the progress of the boat could

only have been 132 feet at each revolution, or 39,204 feet during the time, instead of 37,000 actually performed, thus showing a loss of less than 6 per cent. Respecting the engines for working the propeller, it was observed, that they may be made much stronger and more compact than ordinary marine engines, in consequence of the power being applied directly to the shaft which works very near the bottom; this, for seagoing vessels, will be very important, and their original cost must be considerably reduced, as all the paraphernalia of shafts, wheels, wheel-guards, &c., will be dispensed with. We were struck with the great regu. larity of the motion, not the slightest jar being perceptible. The engines consist of two cylinders 16 inches in diameter, with 18 inches stroke, and are worked by steam of a pressure varying from 35 lb. to 55 lb. to the square inch; their construction is extremely simple, and evinces a knowledge of steam machinery in the inventor which is calculated to give additional confidence in the success of his propeller in all the varieties of its application for canal, river, or ocean navigation.-Times.

ROYAL INSTITUTION.-MR. BRANDE'S LEC, TURE ON STEEL.

March 1st.-The Conversazione.—Mr. Palmer had on the table his pneumatic filter applied to the making of coffee, (as suggested by a friend of ours,) and exhibited filtered infusions both cold and hot. The former possessed in a much greater degree the fragrance of the berry, but as to its other qualities we say nothing. Mr. Macdonald sent some specimens which are now said to be scarce, though we know not for what reason-of those interesting deposits from the water of the baths of San Fillippo, in Tuscany, which being received in suitable moulds, take any form at pleasure. In the present instance it was that of portrait medallions; the appearance is more that of wax than of marble.

The Lecture.-Mr. Brande, on Steel. The lecturer gave a slight notice of the history of the metal; described the process of its manufacture, explained the difference between blister sheer and cast steel; exhibited specimens of each, and of the crucibles employed in the latter operation; pointed out the chemical and mechanical distinctions between cast iron and steel; and enlarged on those pecularities of steel, as distinguished from other metals, which confers on it so

many valuable properties, available in arts, manufactures, and science, illustrating the whole with appropriate experiments.

The great body of observations filling up the above outline, would, in point of information, be too familiar to the readers of the Mechanics' Magazine to require notice; we therefore select only those which it is thought may be interesting. In the lecturer's opinion, steel was known to the Egyptians, for he could not conceive the possibility of executing their stupendous monuments, without a knowledge of its use; he supposes that they derived it from India. He drew attention to the rather singular fact, that there is at present imported into this country, from the East Indies, a very pure iron, and of which the Vauxhall steel company avail themselves in making steel. He observed, in regard to the process of cementation, that

431

it may be conceived, either that the particles of carbon pass by transference through the substance of the iron, or else, that the carbon penetrates it in the form of gas, and thus effects the union constituting steel. In adverting to the doubts which have been entertained respecting the chemical nature of steel-alluding, we believe, to a remark of Dr. Dalton, that he had never been able to detect any carbon in it-Mr. Brande said, that it was his firm belief it could not be made without carbon. He admitted, however, that phosphorous is an essential ingredient in good steel, and to its existence in animal charcoal, he attributed the superior efficacy in the process of case-hardening, of that kind of charcoal to the common sort.

We subjoin tables of the constitution of cast-iron and steel, as exhibited by Mr. Brande :

Taking the liberty to append a few observations of our own, we would remark that in regard to the use of steel by the ancient Egyptians, it is not probable that either they or the Hindoos were acquainted with the art of making it by cementation, but it is not unlikely that they used a kind of native steel, or wootz, or that they adopted that primitive practice, which exists even at the present time, particularly in Styria, of decarbonising cast-iron, where, in consequence of the process falling short, by one or two stages of complete refinement, it sells even at a lower price than the pure iron obtained at the same time.

With respect to the two distinct conceptions of the mode in which cementation is effected, we do not perceive that any material difference is involved in those distinctions, unless we further suppose, that the outer portion of metal is overcharged with carbon, and parts with its excess to the next, and so on, until the middle is reached; but in this case we should expect to find

100.00

100.00

On

that by the time the interior has become steel, the exterior would be converted into cast-iron, or that at least a greater difference of stratification would be produced than is observable. Should, however, this be the real effect, and we are not certain that it may not be so in an extreme case, still it would not be conclusive in favour of the mode by transference, for a greater absorption of carbon would take place near the surface, by the mode of gaseous penetration. the other hand, though it is certain that the gaseous form of carbon is found sufficient for the formation of steel, yet the inference from this fact in favour of the gaseous mode is also not conclusive, for the carbon may still be imbibed only at the surface. May it not, however, be asked, in behalf of the latter mode, whether the mere density of iron could possibly prevent its fermentation by gaseous carbon? Whether there would not be required a repulsive force? Whether it is not to this force that we are indebted for the retention of the gases in vessels ? and, whether the gas of carbon would not penetrate freely enough, when this force is nullified by that which is connected with chemical attraction? But there is no end to conjecture on the subject of molecular action, and it will never be otherwise until new mediums of research are brought within our reach.

No one will question the great ability of Mr. Brande as a lecturer, but we could almost indulge the wicked wish of being able to temper with, and manoeuvre a little, the progress of the clock in order to see the good effect for once of surprising him out of the extreme deliberateness of his delivery; but we question whether he would not rather forego half of his lecture, than quicken his paces in the least. Unfortunately, also, he does not think it necessary to raise his voice higher than in common conversation, but though his enunciation is so beautifully distinct, that with listening attention, he may be heard in most parts of the theatre, yet the continual effort to give such attention, especially at this season of the year, when every body thinks it to be his duty to cough, soon becomes very fatiguing, and at last so painful as quite to mar the pleasure of hearing him lecture.

NOTES AND NOTICES.

Chronometer Prizes.-Sir,-A recent number of your Magazine (No. 811,) contains an article signed "Philo-veritas," and entitled "Chronometer Premiums-Abuse of official influence," in which a statement regarding the number of our chronometers which have obtained prizes at Greenwich is brought forward, in apparent contradiction of a certificate granted by the Astronomer Royal to Mr. Carter, of Cornhill. It has come to our knowledge that copies of the number of the Mechanics' Magazine referred to have been sent to different persons, amongst whom we may name the Astronomer Royal himself, and the Hydrographer of the Admiralty, labelled "with Parkinson and Frodsham's compliments." As we had no concern whatever, directly or indirectly, in writing, communicating, or publishing the article in question, and as we have no means of knowing whether the deception attempted on Mr. Airy and Captain Beaufort may not have been practised on other gentlemen, we trust you will not refuse, in justice to us, to publish this protest against so unjustifiable a use of our name. We remain, Sir, your obedient servants, Parkinson and Frodsham.

Change Alley, March 12, 1839.

Great Western Steam Ship Company.-A halfyearly general meeting of the proprietors of the Great Western steam-ship was held in Princesstreet, Bristol, last week. Mr. Maze took the chair. Mr. Claxton read the report, which stated that the company's first ship had disproved all unfavourable auguries, and promptly rewarded the enterprise of the projectors. It was impossible to speak too highly of the qualities of the Great Western steamship; after having run 35,000 nautical miles, and encountered 36 days of heavy gales, her seams required no caulking, and when she was docked she did not show a wrinkle in her copper. The average of her passages out was 15 days, and home 13 days; the shortest passage out was 14 days, aud the shortest home 124. About 1,000 passengers had gone in the ship. After alluding to the great expense necessary to combine speed, security, and enjoyment, it expressed a hope that through the liberality of the American Congress the duty of 2d.

per bushel on coals would be given up, and thus a saving of nearly 1,000l. a year would be effected. The company have decided on constructing their next vessel of iron, for which the preparations are far advanced. It appeared from the statement of accounts, that after paying 2,0007. for additions to the ship, and insurance to October next, 1,5007. for goods damaged in the hurricanes in October last, and upwards of 2,0001. being set apart for a reserve fund, there remained from the profits sufficient for a dividend of 5 per cent., making with the former one of 4 per cent., 9 per cent. for the year. The report was unanimously adopted.

Iron.-Every person knows the manifold uses of this truly precious metal; it is capable of being cast in moulds of any form; of being drawn out into wires of any desired strength or fineness; of being extended into plates or sheets; of being bent in every direction; of being sharpened, hardened, and softened at pleasure. Iron accommodates itself to all our wants, our desires, and even our caprices; it is equally serviceable to the arts, the sciences, to agriculture, and war; the same ore furnishes the sword, the ploughshare, the sythe, the pruninghook, the needle, the graver, the spring of a watch or of a carriage, the chisel, the chain, the anchor, the compass, the cannon, and the bomb. It is a medicine of much virtue, and the only metal friendly to the human frame. The ores of iron are scattered over the crust of the globe with a beneficent profusion, proportioned to the utility of the metal; they are found under every latitude, and every zone; in every mineral formation, and are desseminated in every soil.-Dr. Ure's Dictionary of Manufactures.

British Association.-The period for holding the ensuing meeting, which was left for the decision of the council, has now been fixed. The first meeting of the general committee will be held at Birmingham on Saturday, August 25, and the various sections for scientific business will meet on the 27th, and through the week. The local council and committees are alreadiy busily engaged in making the preliminary arrangements.

Ericsson's Propeller Company.-A company has been formed for building a ship of 1,000 tons burthen, to run between England and the United States, fitted with Captain Ericsson's patent propeller (a very favourable experiment with which is detailed in another part of our number.) The working plans of the vessel and engine have been prepared, and everything is in a state of forwardness for the commencement of operations. We observe that Mr. Ogden, the American consul at Liverpool, well known for his scientific attainments and enterprise, is one of the directors of this undertaking, which is called the "Atlas Steam Navigation Company."

Light-drawn-pictures.-Our vivacious Parisian neighbours have certainly the faculty of making the most, in words, of anything they chance to lay hold of. "M. Daguerre's ingenious discovery," says the Paris correspondent of the Post, "which has assumed the name of 'Daguerrotype,' continues to excite very great curiosity and admiration. It is affirmed that the Emperor of Russia has offered 500,000f. for his secret, and that he has declined the munificent reward. It is not likely that his friend, Mr. Arago, will succeed in obtaining a larger national one from the Chambers." Mr. Talbot's communications to the Royal Society have made the processes public property here, had they not been so before. Sir John Herschel has turned his attention to the subject and has already obtained pictures from the light of Daniell's great galvanic battery; Sir David Brewster too, has commenced an investigation into the matter.