1896.] 11 J [Sachse. 



2283. C. Hanford Henderson, Ph.D., Philadelphia. 



2284. Chas. Sedgwick Minot, Harvard Univ., Mass. 



2285. L. H. Bailej, Ithaca, N. Y. 



2286. Wm. H. Welch, M.D., Baltimore, Md. 



2287. T. Mitchell Prudden, M.D., New York City. 



2288. John Trowbridge, Harvard Univ., Mass. 



2289. Nikola Tesla, New York City. 



2290. Arthur W. Wright, Ph.D., New Haven, Conn. 



2291. Prof. Henry A. Rowland, Baltimore, Md. 



2292. Prof. Arthur W. Goodspeed, Philadelphia. 



2293. Prof. Michael I. Pnpin, New York City. 



2294. Thos. A. Edison, Orange, N. J. 



2295. Edw. C. Pickering, Cambridge, Mass. 



2296. Frank H. Cashing, Washington, D. C. 



The Joly Process of Color Photography. 



By Julius F. Sachse. 



{Read before the American Philosophical Society, May 15, 1S96.) 



I have the honor to present to j'our notice this evening, by courtesj- 

 of Mr. Richard Barkley, of New Yorlv, a series of specimens illustra- 

 ting the so-called "Joly " process of color-photography. 



They are the same as were lately shown before the Royal Society of 

 England, and excited considerable attention. 



This process, although it depends upon the three primary color sen- 

 sations, differs materially from all others thus far brought to the notice 

 of the public, because but a single photographic manipulation is required, 

 and no apparatus is needed other than such as is used in ordinary 

 every-day photographj-. 



This process consists in making a negative through a closely-lined 

 screen, ruled in three colors, viz., orange, yellow-green and blue-violet. 

 The screens used in the specimens here shown were made with an ordi- 

 nary ruling pen, such as is used by draughtsmen, and the lines number 

 about two hundred to the inch. A finer ruling in the future will make 

 the lines which we now see in the specimens before us less prominent. 



It will be noticed that Prof. Joly, in his "taking" screen, which is 

 here before you, has substituted, for the usually accepted primary color 



