While GW worked as a practicing professional land surveyor in the latter 1740s and early 1750s, he used John Lonem as his head chainman, at least for approximately half of his surveys. Lonem did not work with GW in the summer or fall of 1750 but carried the chain for him on about half of his surveys in the fall of 1749 and the springs of 1751 and 1752 and on nearly all of his surveys in the spring of 1750. Lonem, like other chainmen, used a surveying chain to measure distances.