One of the abandoned (part-worked) stone blocks in the stone sorting yard.
Note the pair of opposing grooves on either side of the split in the block (to the left of the penny, which has been included for scale). These grooves were formed when a single hole was drilled into the block. A hammer, a 'plug' and a pair of 'feathers' were then used to split the large block into two smaller blocks. This block was almost certainly part-worked during the construction of the Settle-Carlisle Railway.