INSTRUMENTS FOR OBSERVING 19 
Price Current Meter 
47. The Price current meter (fig. 14) was originally designed by Assistant Engineer 
W. G. Price, Corps of Engineers, U.S. Army. It is designed to measure the velocity 
of the current but not its direction. The instrument consists essentially of a wheel 
made of a number of conical cups which is free to rotate with the current and indicates 
velocity by the rapidity of the rotation. An electrical connection enables an observer 
with an earphone to count the number of revolutions during any interval of time, the 
corresponding velocity of the current being afterwards determined by means of a rating 
table. It may also be electrically connected with an automatic recording device. 
48. The meter wheel shaft, also known as the cup shaft, has at its lower end a 
bearing which rests upon a pivot point set in the supporting yoke. The upper end of 
the shaft extends into the contact chamber which is secured in the upper part of the 
yoke and in which electrical contacts are made as the shaft is rotated. Provisions are 
made to register each individual turn of the shaft for comparatively weak currents or 
to register each 5 turns for the stronger currents. 
49. For the single-count device an eccentric on the upper part of the cup shaft 
contacts on each revolution a small wire spring extending from a plug screwed into the 
contact chamber. For the penta-count device, the shaft is provided with a worm gear 
which engages a gear wheel in the contact chamber. Projections on the gear-wheel 
FIGURE 14.—Price current meter. 
