Excerpt from Electric and Magnetic Measurements Errors of various kinds arise in making measurements, the most important of which are the following: Errors of observation, due to lack of ability on the part of the observer to make accurate readings. Simple mistakes, which grow less troublesome as the observer gains in training and experience. Instrumental errors, due to incorrect calibration of scales or to faulty adjustment of comparison standards. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Excerpt from Electric and Magnetic Measurements and Measuring Instruments The following volume has been written for the use of those who have to do with electrical and magnetic measurements in one form or another, and as these must be made in practically all branches of the profession, from the simple testing out of lines and resistances to the most elaborate determination of designs, it is hoped that its Sphere of usefulness will be quite large. The subjects have, throughout, been approached with a View toward their use by users, not manufacturers, of measuring apparatus, that is to say the book is in no sense intended as a treatise on the design and construction of instruments, the circle interested being decidedly limited. Descriptions are, however, given of apparatus as well as of methods of test, because knowl edge of the manner in which a principle is utilized in concrete instruments often suggests, to one having a determination to make but is at the same time without the particular form of appliance ordinarily employed for that purpose, means of adap ing thereto some other device which is at hand. Further, in illustrating examples of instruments for different kinds of work, there has been in mind the idea that these will enable engineers to decide, with the aid of their general engineering knowledge, which are the best suited to their particular requirements. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

"Joseph F. Keithley, a modern pioneer of instrumentation, brings you a fascinating history of electrical measurement from the ancient Greeks to the inventors of the early twentieth century. Written in a direct and fluent style, the book illuminates the lives of the most significant inventors in the field, including George Simon Ohm, Andre Marie Ampere, and Jean Baptiste Fourier. Chapter by chapter, meet the inventors in their youth and discover the origins of their lifelong pursuits of electrical measurement. Not only will you find highlights of important technological contributions, you will also learn about the tribulations and excitement that accompany the discoveries of these early masters. Included are nearly 100 rare photographs from museums around the world. THE STORY OF ELECTRICAL AND MAGNETIC MEASUREMENTS is a ""must read"" for students and practitioners of physics, electrical engineering, and instrumentation and metrology who want to understand the history behind modern day instruments." Sponsored by: IEEE Instrumentation and Measurement Society

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Excerpt from Absolute Measurements in Electricity and Magnetism To the late Mr. E. B. Rosa and his colleagues of the physical staff of the Bureau of Standards at Washington I am under many Obligations. They tested and used my suggestions as to standards and formulae of inductance, and constructed an accurate electrodynamometer of the special dimensions recommended in my Phil. Mag. Paper of 1892, and in the First Edition of this book. They have carried in their writings the investigation of the accuracy of formulae, and the allowance for errors of different kinds, to a high pitch of perfection. Their numerical comparison of formulae and their exact computation of the constants of apparatus have not been such as to attract popular attention and applause, but it has been none the less of enormous value to scientific progress. This merit it has in common with the whole work of the British Association Committee on Electrical Standards and of all those scientific men who have laboured at the subject of absolute electrical measurement. This task of founding a system of absolute measure ments was forced upon science by applications to submarine telegraphy, and it is not too much to say that without such a system not one of the immense and varied range of practical applications could ever have been made. I am indebted to my friend and former pupil, Professor E. Taylor Jones, who has made an elaborate theoretical and experimental study of the induction coil, and is an acknowledged authority on that subject, for the account of the action of such apparatus, which appears in Appendix I. The Table of Contents and the Index have been constructed by my eldest daughter, to whose unfailing patience and ready help as amanuensis I have had continually to turn. I wish finally to acknowledge the care of the readers and compositors of the University Press, which, by comparison of references, and other wise, has saved the text from many inconsistencies, and increased its accuracy. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.