He and John Laycock and Stanley Jeffcoat initiated what is referred to as  "gritstone climbing" in England, bouldering on large blocks at the base of the cliffs, and roping up to climb the edges and faces above.
The passage describes a new style of rock climbing called "gritstone climbing" developed by John Laycock, Stanley Jeffcoat, and the unnamed individual. This method involves bouldering on large rocks near the base of cliffs before using ropes to ascend the steep walls and faces above.