January 30, 1903.] 



SCIENCE. 



193 



miley's process of color photography. 



For two years or so Mr. Miley, a photogra- 

 pher of Lexington, Va., has been using a 

 process of color photography which seems to 

 present distinct advantages over any process 

 heretofore devised, and which promises to make 

 color photography a complete success. Mr. 

 Miley is a skilled photographer, and has spent 

 much of his time in experimentation, often 

 with no little success. His process of color 

 photography is the outcome of some of these 

 experiments, and can not be considered as a 

 development of any of the other processes in 

 use, none of which has such practical possi- 

 bilities. Mr. Miley has made and sold many 

 of these color photographs during the past 

 two years, while he has, at the same time, 

 been experimenting to improve the process. 

 It is only recently that he has been prevailed 

 upon to take out patents. A paper on Mr. 

 Miley's work was read before the Chemical 

 Section at the recent meeting of the Amer- 

 ican Association in Washington by Professor 

 W. G. Brovm, and specimens of the work in 

 its various stages were exhibited, and I am 

 permitted to give a description of his process 

 to the readers of Science. 



Negatives are prepared by the tri-color pro- 

 cess, using three sensitized plates and three 

 screens, red, green and violet, respectively. 

 For the red screen an orthochromatic plate, 

 flowed with a eyanin solution, is used; for 

 the green screen an orthochromatic plate, and 

 for the violet screen a plain gelatine bromid 

 plate. There are thus obtained three nega- 

 tives, varying in density in the different 

 areas according to the color values of the three 

 primary colors in the corresponding areas of 

 the object taken. 



Prints are made from these negatives by 

 the use of bichromatized gelatine pigment 

 paper (carbon tissue). The pigment papers 

 used are red, yellow and blue. The blue paper 

 is printed from the red screen negative, the 

 red paper from the green screen negative, 

 and the yellow paper from the violet screen 

 negative. These three printed films are then 

 superposed upon transfer paper, the result 

 being a color photograph, imitating the colors 

 of the object with a marvelous degree of 



fidelity. This process has been used to copy 

 oil paintings, which will probably in the 

 future be its greatest value, as well as to re- 

 produce flowers and fruit in their natural 

 colors. To obtain most accurate results great 

 care and much experience are necessary. In 

 Mr. Miley's hands the process seems exceed- 

 ingly simple. The points along which expe- 

 rience is most necessaiy, and along which also 

 improvements may be made, seem to be the 

 following: choice of screens so as to give the 

 full color value of the object; corresponding 

 choice of pigment papers to match the effects 

 of the screens; choice in time of exposure 

 through the different screens, so as to attain 

 the true color value of the object; density of 

 printing films ; order of superposition of films. 

 While great improvements will be made in 

 the future, the process itself can no longer be 

 considered in its experimental stage, as it 

 has now been in commercial use for upwards 

 of two years. It constitutes one of the great- 

 est advances in the history of photography. 

 Jas. Lewis Howe. 



CUBBENT NOTES ON PHYSIOGBAPHT. 



PHYSIOGRAPHIC DIVISIONS OF KANSAS. 



An essay by G. I. Adams under the above 

 title indicates the salient characteristics of 

 several natural areas, and illustrates their 

 boundaries on a map (Bull. Amer. Geogr. 

 Soc, XXXIV., 1902, 89-104). One here 

 finds good illustration of the value and aid 

 of physiographic explanation as a means of 

 geographic description; the reason for this 

 being that the relief of the state is on the 

 whole moderate, and the elements of form 

 hardly pass beyond the range of plain, hill, 

 escai"pment and valley, so that empirical de- 

 scription is baffling and confusing. The divi- 

 sions proposed are all based on structure as 

 modified by erosion and deposition. Cherokee 

 lowland, a subsequent lowland twenty-five 

 miles wide, crossing the southeastern corner 

 of the state from Missouri to Oklahoma, is 

 generally worn down to low relief on a belt 

 of weak coal measures, but preserves occa- 

 sional sandstone mounds on the divides; its 

 streams flow in wide, flat-bottomed valleys 

 bordered by low gentle slopes, the whole area 



