History of the Periyar Project. 18 Collotype Plates.

Folio size (large archival report). It details the construction of the historic Periyar Dam (now known as the Mullaperiyar Dam) and diversion scheme in British India. The project diverted water from the west-flowing Periyar River eastward through a tunnel into the dry Vaigai River basin in the Madras Presidency to irrigate arid lands. 18 very fine Collotype Plates. Collotype Plates (or Fine Photogravures): This is the exact photomechanical process used for high-end 1890s government engineering folios. A glass plate coated with light-sensitive bichromated gelatin was exposed to a photographic negative. When inked, the gelatin transferred a continuous-tone, rich black-and-white ink image onto the smooth, heavy plate paper. Please view the images, the print is clear any very good, the title, preface are loose. Damage to the large fold out map, there are many blank pages in the 2nd half of the book. All text is there with the 18 rare photo's and a lot of graphs and diagrams. All images are photographed in natural light, no lights used to enhance colour or diminish shadows. Registered postage. Tracking details will be forwarded to the purchaser.…