Thoreau writes in his journal:
2 P.M.—To Bare Hill road . . .
At 7 P.M. the river is fifteen and three fourths inches above summer level . . . (Journal, 13:369-371).
Thoreau also writes to E. H. Russell (The Writings of Henry D. Thoreau (ucsb.edu); MS, Princeton University, Princeton, N.J.).