1) The name given in the north-east to a seam about a foot thick which was not considered worth getting.
In most coal-mines there were several kinds of coal and some of them were considered to be not worth getting. The name Crow Coal was given in the north-east to a seam about one foot thick which was included in 1708 among the ‘foul or bad coals’. Nevertheless, it was good enough in some districts to burn lime and it was certainly used in Yorkshire: 1690 more in Coales gott in the Craw bed, Farnley
1761 advance in getting Craw bed, Tong
1767 12 loads of crow coal leading, Tong.