Practical Surveying and Computations is long established as a major land surveying textbook: the first edition was published as Practical Field Surveying and Computations (A L Allan, J R Hollwey and J H B Maynes). The book has been completely rewritten in this second edition to take account of the profound changes in surveying methods and applications that have resulted from the introduction of electronic instrumentation and computerized data processing systems. These new developments and capabilities in metrology give today's surveyor unprecedented freedom in the numerical handling of data. As a result, the emphasis is shifted from the need for detailed understanding of instrument function to the avoidance of blunders at the data-gathering stage and the ability to appraise computer output in the light of fundamental principles: that is, a quality control system. The explanations and examples in this new edition equip readers to select those procedures and techniques that are most reliable, accurate, cost effective and appropriate to the problem tackled. Dr A L Allan, FRICS, is Reader in Surveying in the Department of Photogrammatry and Surveying at University College London.Allan, A. L. is the author of 'Practical Surveying and Computations, Second Edition', published 1993 under ISBN 9780750603935 and ISBN 0750603933.