An early 19th century attempt to try the Great Rake under the toadstone; there are picked numbers on the wall which appear to relate to the distance to the vein. The level eventually reaches a winze, the reason for this is that they hit the toadstone before they hit the vein, had to go down under it, only to find that the vein is pretty much a 3ft wide streak of calcite when they eventually got to it. There is a lower level which does carry on a bit further, possibly chasing scrins but again there doesn't seem to have been anything worthwhile.
References
PDMHS bulletin vol.4 Part 6 1971
Lead Mining in Derbyshire vol3
PDMHS newsletter
Information courtesy of Adam Russell.