32 
THE HALL. 
to rocks of this formation, some of the palaeozoic limestones in 
certain districts, as near Bristol, being lithologically true oolites. 
The famous Bath stone is a limestone of well-marked oolitic 
structure, occurring in that part of the lower oolitic series 
distinguished as the Great Oolite. 
Bath stone possesses an agreeable warm tint, is worked with 
great ease, and may be obtained in blocks of large size, but some 
of it certainly does not possess great durability when exposed to 
the atmosphere of large towns. Certain varieties, however, such 
as that known as “ Box Ground,” have acquired reputation as 
weather stones which have stood admirably in Malmesbury 
Abbey and other ancient buildings. Bath stone is extensively 
employed, by reason of its softness when fresh-quarried, for 
ornamental mouldings and sculptured decorations. One pecu- 
liarity connected with this and other free-working limestones is 
that they become harder on their surfaces by exposure to the 
weather. This is said to arise not only from evaporation of 
the “ quarry water,” but from a slight decomposition taking 
place, which removes most of the softer particles, and leaves 
the hardest and most durable to act as a protection to the 
remainder. 
The principal quarries, or in most cases underground workings, 
of this stone are those of Box, Combe Down, Monk’s Park, Far- 
leigb, Stoke, Westwood, and Corsham Down. In the restoration 
of Henry the Seventh’s Chapel, the Combe Down stone was 
employed, costing about 40,000£. 
A process has recently been used for increasing the durability 
of Bath stone, and similar stones, by treating the surface with 
a solution of some fluosilicate. 
The Inferior Oolite , so called in reference to its position at 
the base of the Oolitic series, yields some famous freestones, of 
which numerous specimens are here exhibited. The Lincolnshire 
Limestone, belonging to the Inferior Oolite, is quarried in many 
localities in the Midlands, as at Ancaster, near Grantham, and 
at Weldon in Northamptonshire. Ancaster stone was used in 
Lincoln Cathedral; Ketton stone in parts of Ely and Peter- 
borough Cathedrals ; and Barnack stone was a favourite material 
with ecclesiastical architects as far back as the seventh century. 
In the West of England the Inferior Oolite yields excellent 
building stones, (.'specially in the Cotteswold Hills ; examples of 
which are shown from Painswick, in Gloucestershire, and other 
localities The Doulting stone, from near Shepton Mallett, was 
used in parts of Wells Cathedral and Glastonbury Abbey. Ham 
Hill, in Somersetshire, yields a false-bedded, sheily limestone, of 
warm brown colour, reputed to be very durab’e, and recently 
used in several large buildings in London. 
Immediately beneath the Oolites comes the broad band 
of the Lias formation — the term being probably a corruption 
from layers, as indicating the mode of occurrence of some of 
