144 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
board as’ain, from balf an hour to six or eiglit hours later. Observing this, it soon 
occurred to us that something might be done to develop this field of inquiry, and 
various devices were tried from time to time with greater or less success until, on the 
8th of May 1885, the present form of surface tow net, devised by the writer, was first 
used and became a part of the regular scientific outfit. 
IMPROVED SURFACE TOW NET. 
The ring is of g-inch galvanized iron, 4 feet 14 inches in diameter; the net has a 
4-inch niesli, thread 24-G stow, barked, 10 feet in length, same size throughout, and 
has a pocket of the same material 5 feet in length, wldch is formed by turning in a 
portion of the upper end of the net, thus doubling the material for 5 feet from the ring. 
A small cord is passed around the net between the parts, and is included in the turns 
of the lashing which secures the net to the ring. There is a drawstring in the lower 
end of the pocket. 
A mosquito-net lining is secured on the lower inside portion of the net, and hangs 
a foot below it. in order that it may have sufficient slack to insure the outer net taking 
the strain of towing. An ordinary surface net with 12 inch hoop and a silk-gauze 
bag, 20 inches in length, is suspended in the mouth of the larger net by four bridles of 
small stuff secured to the ring; it is intended to collect minute forms that might pass 
through the coarser material of the large net. A 24-iuch bridle with four legs is 
secured at equal distance around the ring, and a 3-inch rope hitched through the bight 
is used for towing. 
To prepare the apjiaratus for collecting: First, lash the lower end of the lining, 
place it inside of the net and lash the latter; rig out the swinging-boom, reeve the tow 
rope through a block near its outer end, and bring the hauling part inboard; hitch 
one end of a small guy rope to the bridle, making the other end fast to the rail. Man 
the tow rope, attend the guy, lift the net carefully over the rail, keeping the ring in 
hand, reduce the speed of the vessel to about 2 knots, lower the net carefully into the 
water by the guy, and haul in the tow line until the ring floats at the desired depth. 
The net is taken in by hauling on the guy and slacking the tow line as the ring 
leaves the water. It is common practice on board the Albatross to use two of these 
nets at the same time, one at each boom, whenever the vessel is engaged solely in 
surface collecting. 
TOW NETS FOR INTERMEDIATE DEPTHS. 
The possibilities of a tow net of large size, drawn rapidly through the water for 
the iiurpose of taking fish at various depths, were discussed with Prof. Baird in 1882, 
and, to test the matter, a net was made under the direction of the writer, and used 
for the first time on May 8, 1883. 
The ring was made of 1-iuch round iron, and was 10 feet in diameter; the net, 
2-inch mesh and 20 feet in length; the bridle had four legs, which were seized at equal 
distances around the ring, and the steel-wire dredge rope was used as a tow line. 
This apparatus was towed at various depths, from surface to bottom, at speeds 
ranging from 2 to 7 knots per hour, but it failed utterly in so far as the capture of 
pelagic forms was concerned; any fish which had sufficient celerity of movement to 
escape a beam trawl would avoid this net. The trouble seemed to arise from its 
