
Figure 27.—Cross-secTIionat viEw of a model 621 Small Price current meter with its penta-contact chamber. 
(From Engineering News, July 2, 1908.) 
ing measurements in shallow streams as well as for 
cable-suspension measurements in deep 
The need for hydrographers to carry two 
making 
streams. 
current meters into the field was finally eliminated. 
The original model of the meter having the new 
penta-contact chamber (and a new yoke) has been 
preserved in the Smithsonian Institution (fig. 26). 
Its penta-contact facility may not have been the first 
to have been installed in a Price current meter, since 
Michael C. Hinderlider of the Geological Survey’s 
Denver office is known to have previously installed a 
number of them in Large Price meters, but this is the 
first Small Price current meter to have been so 
furnished. And it was from this model that the idea 
has been carried into the present. 
The method used to produce single-point and penta 
contacts can be explained best by referring to figures 
22 and 27. ‘The cross-sectional drawing marked AA in 
the first of those two figures shows the construction of a 
single-point contact chamber. ‘The upper end of the 
hub of the impeller has been shaped into an eccentric 
which touches the contact wire every time the impeller 
makes one complete revolution, preducing a click in 
the hydrographer’s headphones. A_ penta-contact 
chamber is shown on the meter illustrated in figure 27, 
where the upper end of the hub of the impeller 
terminates in a worm-gear arrangement, the larger 
gear of which revolves only once while the meter’s 
impeller makes 20 revolutions. Four pins, spaced 90 
degrees (or five revolutions) apart, protrude from one 
side of that large gear. These pins touch the contact 
wire as they go past it, thereby making an electrical 
contact (and a corresponding click in the headphones) 
for every fifth or penta revolution of the impeller. The 
hydrographer chooses whichever of those two facilities 
PAPER 70: WILLIAM GUNN PRICE AND THE 
315-SS4—68——_6 
PRICE CURRENT METERS 61 
is best for the conditions with which he is faced. If 
the water is flowing rapidly, he would select the penta 
If it is 
flowing slowly, he would select the single-point facility 
facility for greater ease in counting the clicks. 
because less time is wasted while waiting for the first 
click of each observation to occur. 
For W. & L. E. Gurley to manufacture a current 
meter containing all of those new ideas involved their 
changing the pattern for casting the yoke and making 
a completely new set of drilling fixtures and jigs. 
Nevertheless, in response to the persuasive enthusiasm 
of J. C. Hoyt, that firm undertook the manufacture of 
the new model. It was assigned their catalog no. 621 
and was generally identified by that number. In a 
circular letter that Hoyt sent to field offices of the 
Survey, he reported that as of May 1, 1908, the first 
two experimental models were in use and that two 
additional experimental models were then being 
manufactured. 
Despite the statement in Hoyt’s letter to Steward 
that the meter “‘was designed so as to use either a 
singlepoint contact chamber or the penta contact 
chamber,” the idea of providing such interchange- 
ability was not conceived of as early as he seems to 
have thought. In fact, several documents written by 
him during the period in question contain strong im- 
plications that he had considered the penta head as 
being suitable for measuring both high and low 
velocities, and there was no intention of providing any 
single-contact facility with any of the 621-type 
meters (see figs. 27 and 28). 
At the time of their introduction, therefore, each 
of the 621-type Small Price current meters was 
chamber, 
equipped with only a_ penta-contact 
but, because the time lost while waiting for that first 
