The “Challenger” Estimates of the Volume of the Gulf Stream

IN the interesting ``Voyage of the Challenger'', just published, Sir Wyville Thomson states (vol. i. p. 371) ``that the Gulf Stream in its restricted sense was, early in May, 1873, at the point where we crossed it and made our observations, about sixty miles in width, 100 fathoms deep, and its rate three knots an hour''. I was much surprised at reading this, as the Admiralty Report on Ocean Soundings, No. 7, p. 12, estimates it at the same point as ``100 fathoms deep, and running at the rate of three miles an hour for a width of fifteen miles, discharging four and a half cubic miles of heated water per hour''.