The General Circulation of the Atmosphere

IN that excellent lecture by Dr. Pernter, delivered before the Scientific Club at Vienna, published by you in NATURE (vol. xlv. p. 593), the theory of the trade winds being occasioned by the rising of the rarefied air at the equator causing an upward current, while cold air from north and south flows in to supply its place, coupled with the earth's rotation to the east, is attributed to Dr. Dove. “Dove was the first person …” But that theory will be found distinctly enunciated by Sir John Herschel in his “Treatise on Astronomy” (1833), where he attributes it to Captain Basil Hall, “where this is distinctly, and, as far as I am aware, for the first time reasoned out.” Herschel was not aware that it had been distinctly reasoned out by George Hadley, F.R.S., in the thirty-ninth volume of the Philosophical Transactions, a century before Basil Hall.