T. L. M. 1. 10 minutes. 2. Sea-side. {_Iod._ 3. {_Exc._ As Le M. {_Dev._ 4. Turner. 5. 3/8 inch. 6. 3-1/8 inches. 7. Diam. lens 3¼ in. Foc. length 17½ in. Maker, Slater. Picture 11½ x 9¼. I have given the development according to the plan usually followed, for the sake of comparison; but where it is desirable to work out the shadows fully, it is far better to give longer exposure in the camera (three times that above given), and develop with gallo-nitrate of the strength used to excite, finishing with gallic acid. The time varies with the subject; a cottage among trees requiring 12 to 14 minutes. Almost all the statements I have seen, giving the time, do so absolutely; it is well to remind photographers, that these convey no _information whatever_, unless the focal length for parallel rays, and the diameter of the diaphragm, are also given: the time, in practice as well as in theory, varying (_cæteris paribus_) directly as the {502} square of the former, and inversely as the square of the latter; and, without these corrections, the results of one lens are not comparable with those of another. When shall we get a good structureless paper? The _texture_ of Turner's, especially his new paper, is a great defect; and its skies are thin, _very_ inferior to the dense velvety blacks obtained with Whatman's of old date--a paper now extinct, and one which, unfortunately for us, it seems impossible to reproduce. T. L. MANSELL. Guernsey. _Conversion of Calotype Negatives into Positives._--At the second meeting of the British Association at York, Professor Grove described a process by which a negative calotype might be converted into a positive one, by drawing an ordinary calotype image over iodide of potassium and dilute nitric acid, and exposing to a full sunshine. Not being able to find the proportions in any published work, can any of your numerous readers give me the required information; and whether the photograph should be exposed in its damp state, or allowed to dry? G. GRANTHAM. _Albumenized Paper._--Mr. Spencer, in the last number of the _Photographic Journal_, in describing a mode of preparing albumenized paper, states he has never found it necessary to iron it, as the silver solution coagulates the albumen the moment it comes in contact with it, "and I fancy makes it print more evenly than when heat has been employed." But Mr. Spencer uses a nitrate of silver solution of 90 or 100 grains to the ounce, while DR. DIAMOND recommends 40 grains. Now as it is very desirable to get rid of the ironing if possible, my Query is, Will the 40-grain solution coagulate the albumen so as to do away with that troublesome process? P. P. * * * * * Replies to Minor Queries.