BRITISH MUSEUM (NATURAL HISTORY). 
21 
TOPOGEAPHICAL DESCEIPTIO]^ OF THE MUSEUM 
AND ITS CONTENTS. 
In following this short account of the contents of the 
various sections of the building, the visitor must bear in mind 
that the principal front faces the south, and that therefore on 
entering the great hall he will be looking due north, with the 
west on his left, and the east on his right hand. 
The Central Hall. 
Immediately confronting the visitor on entering is placed a Central Hall, 
specimen of the bony framework of one of the most colossal of 
animals, for which space cannot at present be found in its 
proper locality — the Cetacean gallery. It is the skeleton of Skeleton of 
the Cachalot, or Sperm-whale {Pliyseter macrocc^plialus), prepared ^P®™'"^^^^®' 
from an animal cast ashore near Thurso, on the north coast of 
Scotland, in July, 1863, on the estate of Capt. D. Macdonald, Pi.E., 
by whom it was presented to the Museum. The Sperm-whale 
is the principal source of supply of the sperm oil and spermaceti 
of commerce. The former is obtained by boiling the fat or 
blubber lying beneath the skin over the whole body ; the latter, 
in a liquid state at the ordinary temperature of the living 
animal, is contained in cells which fill the immense cavity on 
the top of the skull. It feeds chiefly on Cephalopods (squid 
and cuttlefish), and also fish, and is widely distributed through- 
out the warm and temperate regions of both Atlantic and Pacific 
Oceans. The skeleton is that of a full-grown animal. It 
measures fifty feet one inch in length, but wants three of the 
vertebrae from the end of the tail. 
In order to render this skeleton more instructive, and to 
bring it into relation with the elementary specimens of osteology 
in the adjoining bay (jSTo. I., west side), the names of the 
principal parts have been attached to them. This will enable 
the anatomist to trace at a glance the extraordinary modifica- 
tion in the form and relation of its component bones wliich the 
