A. W. S.
Temple.
PHOTOGRAPHIC CORRESPONDENCE.
[By the courtesy of our valued cotemporary The Athenæum, we are permitted to reprint the following interesting communication, which appeared in that journal on Saturday last.]
"NEW PHOTOGRAPHIC PROCESS.
"Henley Street, July 6.
"Your insertion of the annexed letter from my brother-in-law, Mr. John Stewart, of Pau, will much oblige me. The utility of this mode of reproduction seems indisputable. In reference to its concluding paragraph, I will only add, that the publication of concentrated microscopic editions of works of reference—maps, atlases, logarithmic tables, or the concentration for pocket use of private notes and MSS., &c., &c., and innumerable other similar applications—is brought within the reach of any one who possesses a small achromatic object-glass of an inch or an inch and a half in diameter, and a brass tube, with slides before and behind the lens of a fitting diameter to receive the plate or plates to be operated upon,—central or nearly central rays only being required. The details are too obvious to need mention.—I am, &c.
"J. F. W. Herschel.