314 REPORT OF COMMISSIONER OF FISH AND FISHERIES. : 
The improved dredging quadrant is a refinement of the instrument 
described on page 94, Report on the Construction and Outfit of the 
U. S. Fish Commission steamer Albatross. In its present form the 
frame A A consists of two pieces of black walnut 2 feet in length, half 
an inch thick, and 2 inches wide, screwed together with brass screws, 
forming a water-tight joint. Oneof the pieces has a semicircular exten.- | 
sion at its center, which supports the scale C C. | 
Fig. 1 represents the quadrant ready for use. Figs. 2 and 3 show it. 
with the two parts of the frame separated, bringing into view the, 
method of construction. Fig. 4 is an end view at D, and Fig. 5 is a 
sectional view of rod D and spring E. | 
Nomenclature: A <A, frame, of black walnut; B, pendulum, of brass; 
C C, seale, of brass; D, rod, brass, controlling elliptical spring; H, 
spring catch, of brass. | 
The secre a B, 4 inches in length, moves freely on a friction bear- 
ing, and has on ae upper extremity a disk with milled surface. The 
rod, D, is attached to and controls an elliptical spring which, when in 
action, grips the milled surface of the disk on the pendulum and holds 
the latter in position while the reading is taken. The spring catch, E, 
holds the rod, D, in place when it is pressed in for the purpose of dis- 
tending the elliptical spring to allow free movement of the pendulum. 
It engages a slot cut in the rod D, for the purpose. The scale, C C, is 
graduated on each side of the semicircle from a vertical to a horizon- 
tal position, the latter reaching 90°, The instrument is intended to 
measure the angle of dredge rope when operating in deep water, where 
a change too small to be noticed by the eye might carry the trawl many 
fathoms off the bottom. | 
To use the quadrant, take it in both hands, press the rod D with the 
right hand until the spring catch E engages the slot on D; take a 
favorable position and incline the instrument until its upper edge is in 
line with the dredge rope, then press spring catch E with the thumb 
of the right hand, disengaging the rod D, and thus locking the pendu- 
lum B, when the angle from the vertical can be read on the scale. 
We have now the perpendicular (depth) and hypothenuse of a right- 
angled triangle (amount of dredge rope out and its angle). With these 
elements enter table 2 in Bowditch and obtain the third element neces- 
sary to complete the triangle, when it will be seen whether the trawl 
is on the bottom or not, due allowance having been made for catenary 
curve of the rope. 
There have been several changes in the personnel during the year. 
Ensign C, M. Fahs, U.S. Navy, reported for duty September 5, 1892; 
Ensign W. B. Fletcher, U. 8S. Navy, was detached September 14, 1892; 
Passed Assistant Surgeon T. A. Berryhill, U.S. Navy, reported January 
5, relieving Passed Assistant Surgeon F, W. F. Wieber, U.S. Navy, who 
was detached January 6, 1893; Lieut. C. G. Calkins, U.S. Navy, was 
detached January 7, being relieved by Lieut. A. F. Fechteler, U.S. 
Navy, who reported the same day; Ensign W. G. Miller, U. 8. Navy, 
was detached January 25; Passed Assistant Paymaster J.S. Carpenter, 
