FURS--Red Furs may be imitated by using light red and a little masticot, shaded with umber. Gray Furs--black and white mixed and shaded with bistre. Sable--white shaded lightly with yellow ochre. These few directions are quite sufficient for the art, and it is quite unnecessary for me to pursue the subject further. I would, however, remark that the Daguerreotypists would find it greatly to their advantage to visit the studies of our best artists, our public galleries of paintings, and statuary, and wherever else they can obtain a sight of fine paintings, and study the various styles of coloring, attitudes, folds of drapery and other points of the art. In coloring Daguerreotypes, artists will find the magnifying glass of much advantage in detecting any imperfections in the plate or in the image, which may be remedied by the brush. In selecting brushes choose those most susceptible of a fine point, which may be ascertained by wetting them between the lips, or in a glass of water. CHAP. XIII. THE PHOTOGRAPHOMETER. The last number (for March, 1849) of the London Art-Journal, gives the following description of a recent improvement in Photographic Manipulation, and as I am desirous of furnishing everything new in the art, I stop the press to add it, entire, to my work. "Since the photographic power of the solar rays bears no direct relation to their luminous influence, it becomes a question of considerable importance to those who practice the beautiful art of photography, to have the means of readily measuring the ever changing activity of this force. Several plans more or less successful, have been devised by Sir John Herschel, Messrs. Jordan, Shaw and Hunt. The instrument, however, which is now brought forward by Mr. Claudet, who is well known as one of our most successful Daguerreotypists, appears admirably suited to all those purposes which the practical man requires. The great difficulty which continually annoys the photographic amateur and artist, is the determination of the sensibility of each tablet employed, relatively to the amount of radiation, luminous and chemical, with which he is working. With the photographometer of Mr. Claudet this is easily ascertained. The following woodcuts and concise description will sufficiently indicate this useful and simple apparatus. [Illustration: Fig. 30 (hipho_30.gif)]