This Encycropaedia is an outstanding to attempt take full account as incur as possible of history of science and technology from ancient times to twentieth century. At it . same time, an attempt has been made to avoid burdening the text with petty details and maintain a smooth presentation and paint a whore integrated panorama of History of science and Technology. This set has the abvious advantage of competing large departments of knowledge with the most ancient as well, as recent information. It includes History or Physics chemistry, Mathematics, Biological Sciences, Computer. and Technology. In subject matter, an attempt has been undertaken by a careful division of topics to find a better balance. The major part of the material has been extracted from original sources. The point of view in the present work has been intended airways to be objective, impartial and free from conventional platitudes, but this is an ideal and very difficult to attain. The main aim of this encyclopedia is to provide survey of History of science and Technology / with the quest of the young student of the layman. It is hoped that this set will, encourage the reader to make his own investigations of the various scientific phenomena. Throughout the process of compilation and editing of this set, sincere efforts have been made to make this encycropaedia as a ready reference for undergraduate , and postgraduate students of Science, Biology, Engineering, Computer, Marine and Biochemistry and also for those appearing for competitive examinations, research scholars, teachers and alike