188 University of California Publications in Zoology |Vou.9 
stand by the bells, and two sailors to handle the net itself. When 
ready to be lowered the ring from which the net is suspended 
is fastened to the trip which has previously been made secure to 
the cable. The man at the bell, usually the captain or scientist, 
signals the engineer to lower. Just before the net has descended 
far enough, say seventy-five fathoms, he signals a second time 
and the man at the bell passes the signal to the engineer who 
stops the cable. A second signal tells the engineer to raise the 
cable, the man at the meter gives notice when it has risen far 
enough, say fifty fathoms, and the man at the bell signals the 
engineer to stop. The sailors then send the messenger down the 
cable which strikes the trip and closes the net. A haul has thus 
been made from 75 to 50 fathoms, and the net is brought to the 
surface as quickly as possible. When it reaches the surface it 
is hoisted high enough to avoid the railing, then lowered on the 
deck and washed. In all hauls made below the surface the water 
used for washing is filtered through netting of finer mesh than 
that of the net, thereby preventing contamination by surface 
organisms. After washing, the catch is transferred to containers 
as in the case of surface nets, and while one sailor is transferring 
the catch the other is removing the messenger and adjusting the 
net for its next haul. The cable may be raised or lowered at any 
speed but during the interval of each haul the speed is constant, 
thus insuring a uniform rate of filtration. About one minute 
elapses between the time the net reaches the deck and its descent 
for the next haul. 
(c) The Kofoid Net. This is operated in almost the same 
way as the Nansen, although its great weight makes the handling 
more difficult, and impossible on the ‘‘ Agassiz’’ in rough weather. 
Being constructed to make horizontal instead of vertical hauls, 
two messengers are used, the first one to open and the second to 
close the jaws. An interval of fifteen minutes or more usually 
elapses between the sending down of the two messengers. Owing 
to its weight the net tends to act as a sea anchor. This is over- 
come by steaming ahead with one engine while the net is making 
the catch. For a full description of this net see Kofoid, 1911e. 
(d) The Ekman Reversing Water Bottles. If it is desired 
to take water-samples and temperature in say 75, 50, 45, and 10 
