This plan from October 1857 shows a mass of rock blocking the middle of 71st Street between Avenues A and B (now York Avenue and FDR Drive). The diagram at the center outlines the uncovered rock, but beyond the north and south edges of the street it fell to the lot owners, not the street graders, to deal with its removal, as a note at the bottom of the plan makes clear: “The rock taken out to this point where Mr. Pendleton became responsible. The earth excavation on the block was all done.” The diagram records the rock’s features and dimensions, with a tally of its total area running down the right side of the drawing. According to the note in the center, the graders were able to dig out this rock, but more drastic measures were necessary to remove other topographical elements from the street grid. CY