WITH AUTHOR'S PRESENTATION INSCRIPTION

SIEMENS, WILLIAM.

The Electro-Magnetic Practical System of Units.

London, William Clowes and Sons, 1882. 8vo. In the original printed sown wrappers. With author's inscription to top of front wrapper: "from the Author". A few occassional brown spots. Has been bended vertically. Otherwise a fine copy. 7 pp.

First printing, with author's presentation inscription, of Siemens' proposal to create an universal unit of measurement of resistance.

"Siemens' outstanding contribution to scientific technology was his discovery of the dynamo principle, announced to the Berlin Academy of Sciences in January 1867. Having already introduced the double-T armature, the electromagnetic field, and the external load of an electrical generator in a single circuit, thereby avoiding the costly permanent magnets previously used in the field. Other inventors and scientists discovered the dynamo principle at about the same time; but Siemens foresaw the consequences of his "dynamo" for heavy-current, or power, uses and developed practical applications. His company pioneered in using electricity for streetcars and mine locomotives, in electrolysis, and in central generating stations." (DSB)

Order-nr.: 48170