160 
or Halifax beck display the peculiarities of each. The pre- 
sence of a diluvial cliii' on the one bank, or the existence of a 
great fault, whose axis runs North and South along this line, 
would solve the difficulty, but there are no grounds for 
believing either the one or other, and I therefore am inclined 
to refer the fact to the cause assigned, duly considering that 
the inclination of the strata is such that the same elevations 
of the two sides of the rivulet will not exactly correspond ; in 
short, that to the East we are on a variation of the upper Mill- 
stone grit and shale group, whilst on this side we live upon 
the middle member of that formation, assuming my views to 
be correct. 
The town of Halifax is abundantly supplied by the rains 
from two springs in Ovenden, from whence the water is con- 
ducted by drains, and collected into two large reservoirs, 
which were commenced by voluntary subscription in 1826, at 
the suo-o^estion of Mr. Michael Garlick, for the charitable 
purpose of giving employment to the poor, who were then 
suffering from a general depression of trade. These reser- 
voirs, situated nearly a mile to the N. West of the town, on 
high ground, will contain together upwards of five million 
gallons. Besides these, is the Well Head spring, with an 
average discharge of about 80,000 gallons per day, which, 
after having supplied several private residences at the south 
west end, is distributed from a large cistern to the lower parts, 
of the town. 
The Dodgson Clough spring is one of the most simple 
forms of water collected under ground, having its efflux at the 
side of a hill, from a mere interruption to the contiguity of 
stratification. Along the ridge above is a peaty moorland 
soil, of but a few inches thick, and immediately beneath lies a 
deep bed of gravel, through the interstices of which the rain 
readily filters, passing through a loosely laminated consoli- 
dated gravel, a porous blue ragstone, as it is called, and the 
