Randel’s thoroughness is on display on this page that shows him double-checking measurements to assure that the avenues are straight and parallel. On the left page, at the lower left corner, there is a notation “each St. 259.8743”—by which Randel seems to be saying that if you divide the distance between the centerline of 125th Street and that of 137th Street into the 12 blocks between those streets (and allow for the greater width of those two streets) you get an average distance that is 0.1257 feet (about one-and-a-half inches) shy of the canonical 260 feet (a 200-foot block and two halves of two 60-foot-wide streets). The notations and over-sketched dashed lines are how Randel records corrections like these to the rest of the streets in the chart. BH