48 BULLETIN OF THE 
ordinary bait hand-net. As there is a double net of muslin and of fine 
silk bolting cloth extending half-way up the net, everything is kept out 
of the net on its way down. It is an interesting experiment to drag a 
tow-net through the water with the closed point leading, and ta observe 
how completely the sides are collapsed, and prevent the admission of 
water into its lower extremity. The water in the pans in which the con- 
tents of the net were to be washed was always carefully strained through 
fine silk bolting cloth, as was done on the “Blake” with the Sigsbee 
trap. Two pans were thus prepared, one for the contents of the lower 
part of the net,—the closed part, —the other for the examination of 
the contents of the upper part of the net, which remained open all the 
way from the level at which the net was towed to the surface. 
On the 9th of March, at Station 3388, at a depth of 1,168 fathoms, 
fifteen miles from the 100 fathom line and twenty-five miles from the 
nearest land, we made our first trial of the Tanner net. Before sending 
it down to the deeper belts, it was tried near the surface within sight, 
and, the performance of the messenger and the action of the closing 
weights having proved satisfactory, it was sent to tow at a depth of 
400 fathoms, and towed for seventeen minutes, the ship being carefully 
slowed so as to keep the depth nearly uniform, and then the length of 
the wire rope gradually reduced from 570 fathoms, the length of line let 
out on the hypotenuse, to 400 fathoms vertically. The angle of the 
line was carefully checked the whole time by means of Captain Tanner's 
goniometer, so that the variation in the depth at which the net was 
towed could not amount to more than a few fathoms. The messenger was 
then sent down to liberate the weights hanging from the slings suspended 
upon the crank of the stopper, which were to close the bottom part of 
the net. The net was then hauled up at a speed of about four minutes 
to the 100 fathoms, so that for some sixteen minutes the upper open 
part of the net was scooping in the pelagic life in its track. When 
the Tanner net approached the surface, it was found that the bottom 
part of the net had been securely closed, as represented in Plate IT. 
Fig. 6. The bottom part of the net was opened after having tied se- 
curely the upper end of the bottom of the bag, below the loop, to pre- 
vent any part of the contents of the open part of the net from falling 
into it. The lower part of the net was then carefully washed out in 
water which had been filtered, and that water was then examined. 
There was absolutely nothing found in the water. On the other hand, 
the upper part of the bag, which had remained open the whole way up 
from 400 fathoms to the surface, was found to contain very much the 
