Water collecting bottle. Chromed brass cylinder with chromed brass fittings. (Thermometer missing).
In fitted wooden box 36.75" x 9.25" x 7.27" (93.4 x 23.5 x 18.4 cm) containing 2 extension tubes 9.5" (24.1 cm) long; 2 sleeves 6.0" (15.2 cm) long; 1 thermometer holder; 2 spanners; assorted nuts and screws. All of chromed brass.

Constructed for the International Council for the Exploration of the Seas by the Hydrographic Institute Copenhagen, under the supervision of Dr Martin Knudsen. This instrument was designed to bring water samples to the surface while maintaining the temperature at the level at which the sample was taken. The problem with earlier thermally insulated water bottles had been that they took a considerable time to assume the temperature of the sample to be taken. The Nansen-Petterson bottles overcame this by using sea-water as the insulating substance. The walls of water-bottle were made up of concentric cylinders of thin brass or celluloid - and the lid and bottom of parallel rubber plates - so arranged as to let the water flow freely between them, while the water-bottle was open. When the instrument was closed, the communication between the spaces within these cylinders and plates was interrupted, and the water, on account of its large heat-capacity and very limited circulation, served as a good insulator. This instrument was originally used at the Lowestoft Fisheries Laboratory.