 After steadfastly pursuing various methods during thirty years of experimentation, Harrison found to his surprise that some of the watches made by Graham's successor Thomas Mudge kept time just as accurately as his huge sea clocks.It is possible that Mudge was able to do this after the early 1740s thanks to the availability of the new "Huntsman" or "Crucible" steel produced by Benjamin Huntsman sometime in the early 1740s which enabled harder pinions but more importantly, a tougher and more highly polished cylinder escapement to be produced.Harrison then realized that a mere watch after all could be made accurate enough for the task and was a far more practical proposition for use as a marine timekeeper.