Synopses & Reviews
As everyone fully realises, great strides have been made in the progress of engineering practice in recent years, and improvement is still going on. Apart from the steady improvement in design, and in the materials available, the most important factor in engineering progress is accuracy, and it is quite true to say that modern achievements in the performance of engines and machines can largely be explained by the fact that they are constructed and fitted to very much finer limits than those of but a few years ago.
No mechanic, however skilful, can work to a higher accuracy than that of his measuring instruments, and it has thus been necessary for the latter to keep pace with developments; the use of precision instrucments has also been greatly extended, and whereas many engineering works, in former years, kept only one or two micrometeres for use in the tool without the constant use of micrometeres in the hands of every skilled worker.
This book does not presume to be a scientific treatise on measureing instruments or their application; it is written in simple language for the instruction of practical workers who have an intelligent interest in these instruments, and wish to use them to the very best advantage. Neither is it intended to be in any sense a substitute for the skill acquired by practical experience, but it is hoped that it will serve as a useful introduction to the use of the instruments concerned, and in this way will help the worker to attain such skill.
In the preparation of this fully revised and enlarged edition, account has been taken of all modern developments in engineering practic and the design of instruments, and close consideration given to the criticisms, happily very few, which have been made on minor details of the original work. There is ample evidence that the earlier types of instruments are still in extensive use, and it has been considered better to retain matter which may be superfluous than to risk leaving a void in the subjects that should properly be covered.