THE LITERARY GAZETTE, AND JOURNAL OF THE BELLES LETTRES

1840 12 de Dezembro

THE LITERARY GAZETTE, AND JOURNAL OF THE BELLES LETTRES Nº 1247 Pag 803

FINE ARTS VALUABLE IMPROVEMENT IN DAGUERRÉOTYPE To the Editor of the Literary Gazette Sir, - Having been engaged for some time past in investigating the different means of preparing the plates for the action of light in photographic delineations of daguerréotype, in the hopes of being able to render them more sensitive, the result of my experiments has been the valuable discovery, that ehen the bromide of iodine is used instead of the simple iodine, this very desirable oject is attained in a most extraordinary degree. So delicately sensitive are the plates, when properly prepared, that the faintest lights act upon them; even on the dull, cloudy days of November, with a London atmosphere, if not to foggy, and there is sufficient light to produce a picture, it will, by a few minutes’ exposure, be delineated. I have not had an opportunity of experimenting with bright solar light since I made de discovery; but from the experience I have had in the old process during the last summer, I have no doubt that with a clear summer in London the effects will be almost instantaneous. With the light of the ordinary gas a picture of a plaster bust may be obtained in three or four minutes. I remain, sir, yours, &c. John F. Goddart. Late Lecturer on Optics, &c. &c., at the Royal Adelaide Galley.