364 Notes and Comments. U.F.I.,

N E W P R O C E S S O F C O L O R P H O T O G R A P H Y .

Scientists, dabblers in science and ea rnes t ama teu r pho tog raphe r s have been t ry ing for years to discover the secret of p roduc ing pho tograph ic pr in ts in the colors of na ture as seert upon the g round glass of the camera and as projected by the lens upon the sensit ized plate. The lens views and the plate receives the picture in colors, but the negat ive plate is incapable of f ixing any th ing else than form and p roduc ing tha t in fine g rada t ions of l ight and opacity. Color negat ives have been made, but have not been capable of t r ansmi t t i ng color qualities to positives, no r have color posit ives been successfully made by any purely pho tog raph ic principles. Good color effects are produced by super imposing pho tograph ic plates in mechanical p r in t ing processes, but h i the r to there has been little success in chemical reac t ion upon ord inary p r in t ing paper to produce color effects.

Recently, Rudolph I senmann , of 385 Bergen Street , Newark, N. J'., has produced some mos t p romis ing effects in mak ing color pho tog raphs by purely chemical manipula t ion in the simplest possible manner . Wi th ordi- nary pr in t ing-ou t paper, e i ther gelatin, a lbumen or col lodion surfaced, such as is sold by pho tograph ic stock houses, he claims to make pr in ts contain- ing blue, yellow, green and b rown by merely soaking :he pr in ts as taken f r*m the p r in t ing frames in two successive baths with a wash ing between the chemical immersions . The colors find the i r places with wonderful ac- curacy. The rich cerulean blue a r ranges itself in the sky with white cloud effect, and in the sunli t par ts of the water in the foreground, while the water in the shade of the green trees takes up a green ish cast and the browns, and autumnal yellows appear oll the leaves and are reflected in the wate r in some of the pictures. The a r r a n g e m e n t of the colors seems to be natural select ion influenced entirely by the densi ty of parts in the negat ives f rom which the pr in ts are made. Mr. I s e n m a n n says tha t he allows the colors to work out the i r own progress, and never uses any effort to direct them by hand manipulat ion. H e says, further, tha t the process is extremely simple and cheap. He uses no gold in t on ing the pictures, no r does he use hyposulphi te of soda to fix them. W h a t becomes of the free silver he does not say, but he has samples of his color work which have been made and exposed for six months , and he can see no change in the colors.

While i~r. I s e n m a n n ' s results are by no means perfect, they show grea t advance in color pho tography , and give promise of still g rea te r success. He despairs of ever reachilag the reds by this process, but feels tha t he has secured a sat isfactory end by ex t remely simple means.--Scientit~c American Supplement.

I R O N A N D I R O N S U P P L I E S .

Pennsylvania , which makes nmre than half the i ron used in the Uni ted States, produces less than 2 per cent. of the i ron ore mined. Ohio, which comes next to Pennsy lvan ia as an i ron-maker , mines less than o.I per cent. of the total. In bo th cases the ore is b r ough t to the fuel; and this is the policy in this country. Only in Alabama are the ore and fuel found together .