Artistic Photography Asphalt
paper coated with gelatine, it becomes almost essential to adopt M. Artigue's expedient of developing with a soup-like mixture ot ground sawdust and water, as then the image lies in what is in effect a delicate intaglio, and any other attrition than that of the wet sawdust would tend to wipe it out of the intaglio. The sawdust may be of any wood; but it should either be ground in a roller-mill, or should be sifted, and only that used which will pass through a No. 12 (12 meshes to linear inch) sieve. The sawdust being mixed with water of the required temperature to the consistency of soup, this mixture is flushed and re-flushed over the pigmented surface until development is complete - any increase in the temperature of the mixture being regulated by the considerations given above. In spite of the very great things which were expected of the Artigue process when the last edition of this Dictionary was issued, this process has not come into very general use, the more plastic gum-bichromate method having proved more widely applicable. Those interested in further information on the Artigue process can refer to Mr. Pringle's Paper on p. 84 of The Amateur Photographer for January 31st, 1896; but, on the other hand, those who wish to realise the full advantage of modern methods in which the essential principle of the Artigue process is involved, should study the article, Gum-Bichromate, in this Dictionary.
Artistic Photography. This is a subject which cannot well be treated of in the present work. The following books may, among others, be studied with advantage. " Practical Pictorial Photography," by A, Horsley Hinton, Part I. and Part II., is. each, London, Hazell, Watson & Viney, Ltd. ; " Picture Making by Photography," by H. P. Robinson, cloth, 2s. 6d., London, Hazell, Watson & Viney, Ltd.
Artotype. See Collotype.
Asphalt, or Bitumen (Ger.. Asphalt, Judenpech ; Fr., Bitume de Judee Asphalte; Ital., Bitume di Giudea, Asfalto). Synonym : Bitumen, Jews' pitch. It is met with in commerce in black or brown lumps of peculiar gassy and tarry odour, and is obtained from Syria, Trinidad, and other places. Syrian bitumen is the one most generally used in photography as it contains 52 per cent, of the light-sensitive preparation. It is prepared for photographic