1) A survey of underground workings in a mine, to assess how much had been used.
In the Leeds Mercury Supplement of 20 October 1894, ‘latch’ was said to be used in the West Riding with the meaning of ‘to survey underground workings’. In Shropshire ‘to latch’ a coal-pit was to measure how much of the mine had been used and determine what direction the work was taking. This was probably its meaning in earlier Yorkshire references although it is impossible to be certain without more information: 1765 Pd Adam Harrison for latching, Tong
1787 for latching the Coal got … by Messrs Brandling, Beeston: the Pillars of Coal in this Old Coal Works had just been purchased by Charles Brandling from Robert Denison.