APPLIANCES FOE COLLECTING PELAGIC ORGANISMS. 
151 
ing the pevpeiulicular. If the triangle is comj)lete and the net towing from 1 to 1^- 
knots an hour, nothing more is required, but, should it be towing too high, more 
rope or less speed will be requisite; if below the depth, less tow line or an increase 
of speed will soon bring it up. 
The iiractice on board the Albatross is to observe the angle of roiie constantly, 
using a dredging (piadrant designed for that jmrpose, thus regulating the speed and 
resultant angle, the data for the construction of the triangle being obtained from the 
traverse tables in Bowditch’s f^avigation. 
Having towed the net a sufficient length of time, the engines are stopped and the 
rope reeled in, backing slowly, if desired, to keep the net at its proper depth. When 
the line is vertical and the vessel at a standstill, send the messenger down to reverse 
the eccenti’ic tumbler, release the movable weights and close the lower half of the net. 
The impact of the messenger on the friction clamp can be felt by grasping the tow 
rope, but this method is not always reliable below 300 fathoms; a safe practice is to 
time the descent of the messenger for greater depths, allowing about 50 seconds for 
each 100 fathoms. 
Having closed the lower bag, steam slowly ahead and reel in at the rate of 25 
fathoms a minute until the net is on board. The upper portion from the mouth to the 
drawstring remaining open, will usually be found to contain an assortment of speci- 
mens collected on the way up. 
A few turns of a lashing should be taken around the net immediately below the 
drawstring, as soon as possible after the apx>aratus reaches the deck and while it is 
hanging vertically by the tow rope, to avoid the iiossibility of opening communication 
with upper and lower compartments oy the accidental slackening of the drawstring. 
This done, the frame should be lowered gently on deck, the lashing removed from 
the tail of the net and the parts turned back, leaving the inner or silk gauze lining 
exposed; remove its lashing, carefully open the bag over a pan of prepared sea water 
which has been carefully strained to remove any surface forms it might have con- 
tained, and finally rinse the net in it to remove minute specimens adhering to its sides 
or lodged in the numerous folds. 
The contents of the lower bag secured, the drawstring is removed, the upper bag 
turned inside out into a tub of water, and the specimens secured by thorough rinsing, 
after which the lashing is taken off and the net caretnlly washed, usually by towing 
a few minutes if the vessel should be moving slowly through the water; otherwise by 
washing and repeated rinsings until all trace of life is destroyed. The last rinsing 
should be in fresh water, and the frame should be wiped off to prevent oxidation. 
If the apparatus is to be stowed away, remove the apron, unscrew the legs, hang 
the ring with net attached in a convenient place to dry. The tripping lines and the 
drawstring should be hitched to arms or ring and dried. When ready to store, reeve 
the drawstring in place, roll the net up snugly, and stop it with the ends of the 
drawstring; remove the shackle pin and fold the arms across the ring, using the 
tripping lines to hold them in place and to coniine the net as far as possible within 
the ring, thus making a snug and convenient package to handle or store. 
