together with four-hourly observations of the salinity and temperature of
the sea, was carried out during the whole voyage.

In vertebrate zoology Wilson kept an accurate record of birds, and he and
Lillie another record of whales and dolphins. All the birds which could
be caught, both at sea and on South Trinidad Island, were skinned and
made up into museum specimens. They were also examined for external and
internal parasites by Wilson, Atkinson and myself, as were also such fish
and other animals as could be caught, including flying fish, a shark, and
last but not least, whales in New Zealand.

The method of catching these birds may be worth describing. A bent nail
was tied to a line, the other end of which was made fast to the halyards
over the stern. Sufficient length of line was allowed either to cause the
nail to just trail in the sea in the wake of the ship or for the line to
just clear the sea. Thus when the halyard was hoisted to some thirty or
forty feet above the deck, the line would be covering a considerable
distance of sea.

The birds flying round the ship congregate for the main part in the wake,
for here they find the scraps thrown overboard on which they feed. I have
seen six albatross all together trying to eat up an empty treacle tin.

As they fly to and fro their wings are liable to touch the line which is
spread out over the sea. Sometimes they will hit the line with the tips
of their wings, and then there is no resulting capture, but sooner or
later a bird will touch the line with the part of the wing above the
elbow-joint (humerus). It seems that on feeling the contact the bird
suddenly wheels in the air, thereby causing a loop in the line which
tightens round the bone. At any rate the next thing that happens is that