TROPICAL PLANKTON. 2638 
best silk bolting-cloth, known technically as grit-gauze, 
and | used the following four kinds :— 
Net A, 382 meshes to the inch. 
Net B, 72 meshes to the inch. 
Net C, 80 meshes to the inch. 
Net D, 172 meshes to the inch. 
“On the port side of the ship I was allowed to have: 
complete command of a large tap on the main deck, near 
the galley. This brought sea-water from a large tank in 
Artranjemet fer Che ctrng Platten’ om SS Parvin’ 
Any. - Seft. 1997 - WAKA. 
Fic. 1.—Rough diagram to show position of tap, overflow pipe, &c. 
the centre of the ship, which was kept constantly full for 
supplying baths, lavatories, &c., and for flushing purposes. 
The tap I used was an emergency one, rarely required. 
The tank is filled by a pump worked by the engines, so 
that it is in constant action while the ship is steaming. 
The sea-water enters by an aperture, provided with a 
valve, and covered with a grid of three-quarter inch mesh, 
placed in the ship’s bottom, about 8 ft. above the keel 
and 14 ft. below the surface of the sea (fig. 1). 
