A multiplied-deflection A-C potentiometer

P. A. Borden (The Bristol Company, Waterbury, Conn.): In reading Professor Marshall´s paper I could not but be reminded of the somewhat similar work described in a paper which I presented before the Institute several years ago.¹ At that time, however, many of the modern units which Professor Marshall has been able to utilize in making his apparatus portable were not available. As a result, the apparatus which I described could not in any sense be considered as portable. It was possible, though, with this equipment to obtain extremely satisfactory results in the measurement of a-c quantities where the amount of power available for purposes of measurement was negligible in magnitude.