On this day (May 20) in the year 1843, the following article appeared "Niles' National Register." (Baltimore, Vol. XIV., No. 12; May 20,1843; pp. 181-3.) - - - - - - - - - - - - - - - - Under the heading of: INVENTIONS, IMPROVEMENTS, &C. --------------------------------- RADIOGRAPHY, DAGUERREOTYPE, &C. IMPROVEMENTS IN THE DAGUERREOTYPE. From an imperfect report made to the academy of sciences by M. Arago, it appears that M. Daguerre has not yet made public the great improvement in the daguerreotype, announced by him some time ago, owing to his failure in bringing his results to that point of perfection which he hopes to attain. His reluctance in not making them known, imperfect as they yet are, has created much dissatisfaction, and even doubts as to their importance. M. Arago, however, expresses his perfect reliance in them, but acknowledges that he has not seen them. He stated to the academy, from information confided to him by M. Daguerre, that his discovery, in a scientific point of view, bids fair to eclipse even the invention of the daguerreotype. So far as we can understand M. Arago, this discovery consists in submitting a plate, prepared in the usual way, to the action of electricity, which imparts to it so exquisite a degree of sensibility as even to deprive it of the power of receiving distinct impression of the objects reflected upon its surface.--M. Daguerre has not yet been able to contrive means to act with sufficient promptness, in order to expose the entire surface of the plate so as to receive the rays of light and form the impression upon every part of it at once. That is to say, a plate under the influence of electricity, being placed in the chamber of the daguerreotype, receives impressions in the instant of time requisite to open and shut the orifice, of such varied intensity, that the parts of its surface first exposed to the action of light becomes too deeply impressed before it spreads itself over the whole surface, thereby producing only a confused mass of lines. M. Daguerre has not yet been able to succeed in striking out the light with sufficient promptness to admit the rays of light at once upon every part of the surface of the plate. The effect thus produced is similar to that obtained by opening and shutting the orifice of an ordinary daguerreotype, repeatedly, in taking a view which requires ten minutes of continuous exposure to the rays of light. M. Daguerre has not, however, stopped at this point of his discovery, but has invented two methods, the one more ingenious than the other, in order to counteract this imperfection. First, he has employed a substance, the nature of which he has not revealed, to cover the surface of the plate, less sensible to light, than the ordinary combination of iodine and silver; and instead of exposing the plate to the continued and permanent influence of electricity, he interposes this mysterious substance only momentarily, but precisely long enough to receive the action of the rays of light.-- In other words, the plate being thus prepared, and placed in the chamber, it becomes capable of receiving without danger, the action of the rays of light for a given space of time; and in order to impart to it that exquisite sensibility which has already been noticed, it is sufficient to communicate to it a single electric spark; after which, it (the plate) reassuming its ordinary state of inertia, affords sufficient time to withdraw it from the further influence of the rays of light. Thus the operation is terminated; but in such a manner that it becomes possible to delineate a whole assembly in action, with an exact expression of each feature, and movement of every limb. Unfortunately, M. Daguerre has not yet exhibited any of these surprising results, either to the academy or to his learned exponent, M. Arago. He has simply made known a theory, which others, more fortunate than himself, may carry into effect.--Undoubtedly, nothing could be more marvellous than that of being able to paint, in less than an instant of time, the most numerous assembly of persons in action; and the fact of this extraordinary electric influence upon chemical combinations thus exposed to rays of light, is in itself a discovery of the highest interest to the academy of sciences, although it may not be found applicable to the arts; and we think M. Daguerre ought not to have hesitated to make it known, more especially as its effects may be quite as much appreciated in the imperfect impression of the plate, as it could be in a perfect picture. [N. Y. Amer. . . .(and another item under the same heading). . . From the Paris correspondent of the National Intelligencer. "Daguerre has nearly perfected his invaluable discovery, in obtaining instantaneous impression by means of electricity. A slight haze, however, is left on the impression, which he wishes to correct before he exhibits the results of his new process.--He has his envious rivals and ready detractors, who sneer at his discretion, and express doubt, in the journals. His friends boast that he has now rendered it easy to copy the largest assembly of persons, with their momentary countenances and most animated gestures. . . . (Under the present heading are other daguerreian-related articles--all describing various experiments; time does not permit me to transcribe them at this time. --G.E.) -------------------------------------------------------------- 05-20-97