342 
PROCEEDINGS, 1859—1870. 
Stephenson in 2') sees. These experiments tended to ])rove tliat all 
the Safety Lamps were really unsafe in a current of atmospheric air 
and gas when mixed to an ex})losive point ; and secondly, that of the 
lamps now in use the Stephenson is the most reliable. Somewhat 
similar experiments with actual coal-gas had been made in the Oaks 
Pit, the results being practically the same. 
Mr. Richard Carter, C.E., made some observations on Ventila- 
tion in Relation to Colliery Disasters. The fatality which attended 
the explosion in the Oaks Colliery in the December previous, when 
over 300 miners were killed, and a party, at whose head was Parkin 
Jeffcock, who went down to aid in recovering them, were also lost, 
led Mr. Carter to again insist on the common-sense method of ventila- 
tion, which he had described in papers contributed to tlie Society in 
18o7 and 1860 respectively. 
In the succeeding year Mr. A. H. Green contributed a second 
paper on the Coal Measures of the neighbourhood of Rotlierham. The 
Middle Coal Measures, extending between this town and Flockton, were 
described . The lowest of the thick workable coals was the Silkstone, 
Sheffield or Black Shale Coal, a bituminous bed of great purity, 
yielding excellent house coal, and well suited for cokeing. The 
succeeding beds ol coal, with the intervening sandstones and shales, 
are described seriatim. About a hundred yards above the Flockton 
lies a coal or group of coals, about the identification of which, in 
different parts of the field, there was some uncertainty. It was known 
in one place as the Swallow Wood Coal with a dirt parting, altogether 
about 4 feet G inches in thickness. It appears to keep this character 
as far a^ Tankersley, w'here it is worked for local purposes, and is about 
3 feet thick. Thence to Barnsley nothing definite is known about the 
coal, but it is the custom to bore down below the Barnsley Coal, and 
call the bed that could by any possibility be supposed workable by 
the name of the Swallow Wood. This caused considerable confusion, 
and Mr. Green believed that though several beds bear this name, a 
coal may be fixed upon as the equivalent of the true Swallow Wood 
in the Sheffield district. It is. however, of inferior quality, and so 
split up by dirt partings as to be of little worth. Northwards, about 
Darton and Netherton, there are two beds of coal called the Nethertbn 
