WITH THE YORKSHIRE COAL-FIELD. 
95 
other lines of section are in the societies own hands. The distance 
from tlie Penine Chain at the Sheffield and Manchester Railway 
Tunnel to the Holderness coast is about 70 miles, and if ten members 
of the society would each undertake 7 miles, the whole length might 
be completed within a reasonable time. Each individual would have 
to level his own portion either with a spirit-level or theodolite, and 
to measure it with the chain or take its lengths from accurate 
township maps. Each would lay down on paper his observations and 
results, and their respective sheets, when joined together, would 
form the section required. Respecting the scales of these sections 
much may be said, Mr. De la Beche recommends that the scales of 
lengths and depths should be equal, but this suggestion cannot 
always be beneficially acted upon, and it certainly cannot in the 
present instance. The summit of the ridge near Penistone is probably 
about 1800 feet or one-third of a mile above the sea, consequently 
if an uniform scale of three inches to a mile Avere adopted, the length 
of our section when laid down on paper, would be 1 7i feet, and its 
height only 1 inch. The most likely scale for length is 3 inches to a 
mile, and for depth 1 inch to 50 feet, which would make the length 
of the sheet 17i feet, and its depth 3 feet. As before stated these 
different lines of section have been proposed, which may be named 
the Leeds line, the Barnsley line, and the Sheffield line. The first 
to commence at the Leeds and Manchester Tunnel at Todmorden, 
and proceed by Halifax, Leeds, Aberford, and Pocklington, to Barm- 
ston, on the Holderness Coast. The second to commence at the 
Sheffield and Manchester Railway Tunnel, near Penistone, and proceed 
near Darton, north of Barnsley, Brierley, Swinefleet near Goole, 
Cave sands and Cottingham to Aldborough, on the same coast. The 
third to commence at the central axis of the Penine Chain, near 
Castleton, and proceed by Sheffield, Maltby, Tickhill, Bawtry, north 
of Gainsboro', Caistor, to the mouth of the Humber, below Grimsby. 
The second or Barnsley line is preferable because it crosses the coal- 
field in the direction in which its peculiar stratification and richness 
is most fully exhibited, and because the means of obtaining accurate 
geographical and geological information are more abundant, and more 
accessible to the members of this society than on either of the other 
