﻿Vol. 6 1.] WASH-OUTS IN THE MIDDLE COAL-MEASURES. 



339 



14. On the Wash-outs in the Middle Coal-Measures of South 

 Yorkshire. By Francis Edward Middleton, F.G.S. (Head 

 February 22nd, 1905.) 



During the past 20 years the South Yorkshire Coalfield has been 

 developed and explored in the neighbourhood of Aldwarke and 

 Thrybergh, lying 4 miles north-west of Kotherham, where the 

 principal seams have been extensively worked, namely : — 



The Bamsley Seam 7| feet thick. 



The Swallow- Wood Seam 5 feet thick. 



Fig. 1. 



Scale:- 1 1 inches = i mile 



As the workings have extended, large areas have been proved to 

 exist, where the coal has been removed by wash-outs which have 



