In the February, 1964, issue, I was particularly interested in the Mason and Swindler article on the Mason and Dixon Line. On page 29 the following sentence appears: “Horizontal measurements were taken with a Gunter’s chain of sixty-six links on level ground.…” Perhaps the authors will be interested to know that the Gunter’s chain had one hundred links, even though it was only sixty-six feet long. It was one of those developments of the unfortunate English system of measurements which foisted such units as the yard, the rod, the furlong, and the acre upon this country. Four rods of 16½ feet made a “chain” of 66 feet.…