اذا لم تجد ما تبحث عنه يمكنك استخدام كلمات أكثر دقة.
Book digitized by Google from the library of the University of Wisconsin - Madison and uploaded to the Internet Archive by user tpb.
2 volumes 23 cm
Printed in Great Britain
1st edition, by Ernest Wilson, published 1897
I. Direct current.--II. Alternating current