PROF. WALDO, in the American Meteorological Journal for October, recommends the use of instruments for determining the velocity of the wind at sea. In a paper read before the Meteorological Society, I discussed the comparative results, obtained from a great number of observations under all conditions at sea, between two very simple and small anemometers, showing that, although the two instruments were on entirely different principles, the results obtained differed only by about 10 per cent. In a paper read in March last before the Meteorological Society, “Notes on taking Observations at Sea, &c.,” I again urged the desirability of observers using some form of anemometer, so that more uniform results could be obtained, and I gave a table for correcting the apparent velocity of the wind as registered by the instrument for the speed of the ship and for aberration.