Over water, or a surface of ice, sound is propagated with remarkable clearness and strength. … Lieut. Foster, in the third Polar expedition of Capt. Parry, found that he could hold conversation with a man across the harbor of Port Bowen, a distance of six thousand six hundred and ninety-six feet, or about a mile and a quarter. This, however, falls short of what is asserted by Derham and Dr. Young, — viz., that at Gibraltar the human voice has been heard at the distance of ten miles, the distance across the strait.
— Charles Carroll Bombaugh, Gleanings for the Curious from the Harvest-Fields of Literature, 1890