PREFACE THE author hopes that this book will help to fill a small gap in the literature of surveying. There is, unless he is mistaken, no general treatise on tacheometry in which both the practical side of the subject and methods of measurement other than the stadia method are given adequate treatment. The main object of the book is to encourage young surveyors, particularly those in undeveloped countries, to take a greater interest in tacheometry, and especially in that branch of it known as stadia measurement. Surveyors on the whole are inclined to fight shy of ordinary tacheometry. This is largely due to the fact that in text- books on surveying the treatment of the subject is not as practical as it might be. To take one example almost every text-book mentions only one method of reading the staff, namely that in which all three hairs are read to two decimal places in order to provide a check on the accuracy of the readings. This, by itself, is responsible for discouraging many a...