288 
THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
It thus appears that Mr. Lees contributes in his first list 
of Worcester plants 88 new records, 4 of which must be taken 
away from Perry, thus reducing his number from 32 to 28. 
(To be continued.) 
THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
BY BEEBY THOMPSON, F.G.S., F.C.S. 
(Continued from page 255.) 
What is the Storage Capacity of the Material of the 
Bed ? —I am not aware of any experiments bearing upon the 
question of the actual capacity of the Maidstone for water. 
According to Professor Ansted * many building stones will 
absorb about a gallon and a half of water per cubic foot, 
ordinary Sandstones about one gallon, best building stones of 
the Sandstone group four to five pints, and Limestones 
generally more than a gallon. Considering that the Marl- 
stone Rock-bed is a calcareous Sandstone, I thought that an 
average capacity of one gallon per cubic foot would be a fair 
estimate. To test this, four specimens of the rock were 
selected; they were dried first in a water-bath, and afterwards 
on a sand-bath at a temperature of about 200° C., and 
immersed in water for several hours before taking the specific 
gravity, then left suspended in a loop of platinum wire to 
drain before the final weighing. The additional loss by 
drying at the higher temperature varied from '23 to -6 per 
cent, of the total weight of the specimen. The stone 
distinctly lost weight from evaporation of water whilst the 
weighing was being conducted, and therefore, of course, 
during the time it was draining. 
No. 1. Was a hard Oolitic stone of a greenish colour, 
containing fossils. 
No. 2. A ferruginous stone of a ruddy colour, with 
fossils, and some crvstallised carbonate of lime. 
No. 3. A hard green stone closely resembling No. 1. 
No. 4. A hard grey stone, one surface of which had 
become oxidised. 
* “ Applications of Geology to the Arts and Manufactures,” by 
Prof. D. T. Ansted, M.A., F.K.S. 
