Who is Larcum Kendall from Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time and what is their importance?

Larcum Kendall was one of Jeffreys' students. He attempted to make smaller, yet accurate, versions of Harrison's clocks for manufacture. Kendall built a knock-off of Harrison's clock, which was known as the K-1. He built the clock with Harrison's help in order to win acclaim for Harrison's designs. Afterward, he tried to make subsequent clocks for less money, but they didn't work very well.