REVISED AND IN PAPERBACK 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 revised to take account of the profound changes in surveying methods and applications due to electronic instrumentation and computerized data processing systems. These new developments 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.