FAIRLEY : BLOWING WELLS. 
421 
attention has been drawn to them. 
In this paper it is shown — That these currents vary in nature 
and amount with the changes of the barometer just as the volume 
of the air in any closed receiver varies strictly with the atmospheric 
pressure when the influence of temperature has been eliminated. 
Hence the observations may be considered to prove the existence 
of large cavities or series of cavities or fissures in the underlying 
strata adjacent to the wells. In the case of the well at Solberge, 
this cavity has a capacity approximating to ten millions of cubic 
feet. A chamber 217 feet each way — length, width, and height, 
would have nearly the same capacity. 
GLACIAL SECTIONS AT YORK. AND THEIR RELATION TO 
LATER DEPOSITS. BY J. EDMUND CLARK, B.A., B.SC, ETC. 
The various deposits of boulder-clay, sands, gravels, brick-earths, 
warp and peat, near York, have been sufficiently exposed by build- 
ing operations, brick fields, and gravel pits to show this very 
simple relation. Resting upon the deep-seated Triassic rocks lies 
the irregular boulder-clay, which forms all the higher ground, 
reaching in Severn's Mount to 100 feet above the river Ouse. 
Where the stream escapes from between its undulations, the top- 
most layers have been washed and re-arranged as glacial gravels. 
Its hollows have been levelled up with the sediment thus pro- 
duced, forming the brick-earths and warpy clays ; whilst peat 
deposits have completed the work where the depth, elevation, or 
remoteness of the original hollow prevented the brick- earths from 
accomplishing that end. 
An examination of Plate XXIII., Fig. 1, will show the fol- 
lowing relations. 
The glacial beds form the chief feature of the region, not 
only monopolising all the ground more than about 30 feet above 
