56 J. WaterhoLise — The Application of Fltotograpliy [No. 2, 



engineering projects, as well as the ordinary military, administrative and 

 fiscal requirements make the early production of accurate maps a matter of 

 very great necessity and importance, and as skilled lithographic drafts- 

 men and engravers are scarcely to be obtained and must be trained as 

 required, or brought from Europe at great expense, the subject of photo- 

 graphic reproduction as a means of quickly producing and publishing copies 

 of the original maps of the Surveys, is much more important in this 

 country than it is in Europe or other countries where skilled cartographic 

 lithographers and engravers are comparatively numerous. 



The success that had attended the introduction of photography at the 

 Ordnance Survey Office for the reproduction and reduction of maps imme- 

 diately attracted the notice of the Surveyor General of India, and the 

 services of two trained sappers, with the necessary apparatus, having been 

 obtained from England, a small beginning was made in Calcutta in 1862. 

 Owing to difficulties experienced in working photolithography in the peculiar 

 climate of Calcutta, and the unsuitability of the original maps for reproduc- 

 tion by the process, owing to their being coloured and brush-shaded, little 

 advance was made in the practical working of photolithography or photo- 

 zincography in India till 1865, when Mr. J. B. N. Hennessey, of the Great 

 Trigonometrical Survey, who had devoted part of his furlough in England to 

 going through a practical course of instruction in photozincography at the 

 Ordnance Survey Office, Southampton, fairlj established the process at 

 the Office of the Superintendent of the Great Trigonometrical Survey at 

 Dehra Diin. I and other officers of the Survey Department were trained 

 ■under Mr. Hennessey, and, in 1867, photozincography was finally started in 

 Calcutta by Capt. A. B. Melville, who officiated for me during my absence 

 on furlough, and since 1869 it has been carried on under my own supervision. 

 Photozincographic offices have also been established under the Bombay 

 Government at Puna, and at the Kevenue Survey Office in Madras for the 

 reproduction of the maps of the Revenue and Settlement Surveys in those 

 Presidencies as well as miscellaneous work for other departments. In both 

 of these offices the Southampton process of photozincography is used with 

 a few modifications, but in Madras photolithography is also used with 

 equally good results, and is, I am told, preferred for very fine work. 



Before the introduction of photography the publication of the results 

 of the Surveys by the Surveyor General's Office could only be accomplished 

 by the ordinary methods of lithography and engraving ; and though much 

 good work was done in the former manner by the very limited native agency 

 available in this country, many maps had to be sent to England to be litho- 

 graphed, while the whole of the engraving connected with the Atlas of India, 

 on the scale of 4 miles to one inch, was done in England under considerable 

 disadvantages. Even with this help it was found quite impossible that 



