Sunday, and there was a general 'make and mend' throughout the ship, the
first since we sailed. During the day we ran from deep clear blue water
into a darkish and thick green sea. This remarkable change of colour,
which was observed by the Discovery Expedition in much the same place,
was supposed to be due to a large mass of pelagic fauna called plankton.
The plankton, which drifts upon the surface of the sea, is distinct from
the nekton, which swims submerged. The Terra Nova was fitted with tow
nets with very fine meshes for collecting these inhabitants of the open
sea, together with the algae, or minute plant organisms, which afford
them an abundant food supply.

The plankton nets can be lowered when the ship is running at full speed,
and a great many such hauls were made during the expedition.

July 5 had an unpleasant surprise in store. At 10.30 A.M. the ship's bell
rang and there was a sudden cry of "Fire quarters." Two Minimax fire
extinguishers finished the fire, which was in the lazarette, and was
caused by a lighted lamp which was upset by the roll of the ship. The
result was a good deal of smoke, a certain amount of water below, and
some singed paper, but we realized that a fire on such an old wooden ship
would be a very serious matter, and greater care was taken after this.

Such a voyage shows Nature in her most attractive form, and always there
was a man close by whose special knowledge was in the whales, porpoises,
dolphins, fish, birds, parasites, plankton, radium and other things which
we watched through microscopes or field-glasses. Nelson caught a
Portuguese man-of-war (Arethusa) as it sailed past us close under the
counter. These animals are common, but few can realize how beautiful they
are until they see them, fresh-coloured from the deep sea, floating and
sailing in a big glass bowl. It vainly tried to sail out, and vigorously