"The passage between Governor's-Island and Long-Island, formerly called Butter-milk channel, and within the memory of man, both narrow and shallow, is now eight fathoms deep," reported The Medical Repository, February–April 1806, p 433, quoted at The Big Apple: Buttermilk Channel.
Jackson, Kenneth T. (1995). The Encyclopedia of New York City. New York, NY: The New York Historical Society; Yale University Press. pp. 173. ISBN0-300-05536-6
