110 
HISTORIC /IL SKETCH. 
arches under the side-flights of the main staircase at the end of 
the hall lead into another large apartment, with an extreme 
length of 97 by 77 feet measured into the arms of the cross. 
Side galleries. Branching out of the Central Hall, near its southern 
extremity, are two long galleries, each 278 feet 6 in. long by 
50 feet wide. These galleries are repeated on the first floor, and 
in a modified form on the second floor. They are divided into 
bays by coupled piers arranged in two rows down the length of 
the galleries, and planned in such a manner as to allow of upright 
cases being placed back to back between the piers and the outer 
walls, so as to get the best possible light upon the objects 
displayed in the cases with the least amount of reflection from 
the glass, and leaving the central space free as a passage. 
Owing to the nature of the specimens exhibited in one or two 
of these galleries requiring for their exhibition rather table- 
cases than wall-cases, advantage has only been taken to a 
limited extent of this disposition of the plan. These terra-cotta 
piers, however, are constructively necessary, not only to conceal 
the iron supports for the floor above, but to prevent these supports 
being affected in case of fire. Behind these galleries on the ground 
floor are a series of toplighted galleries, devoted, on the east side 
to Geology and Palaeontology, and on the west to Zoology. 
Towers. " The towers on the north of the building have each a central 
smoke-shaft from the heating apparatus, the boilers of which 
are placed in the basement, immediately between the towers, 
while the space surrounding the smoke-shafts is used for draw- 
ing off the vitiated air from the various galleries contiguous 
thereto. The front galleries are ventilated into the front towers, 
which form the crowning feature of the main front. These 
towers also contain, above the second floor, various rooms for 
the work of the different departments, and on the topmost 
storey large cisterns for the purpose of always having at hand a 
considerable storage of water in case of fire. On the western side 
of the building, where it is intended that the Zoological collection 
shall be placed, the ornamentation of the terra-cotta (which will 
be found very varied both within and without the building) has 
been based exclusively on living organisms. On the east side, 
where Geology and Palaeontology find a home, the terra-cotta 
ornamentation has been derived from extinct specimens. 
