U.S. Naval Astronomical Expedition to the Southern Hemisphere, during the years 1849-'50-'51-'52. Lieut. Archibald MacRae, Master S. Ledyard Phelps, Captain's Clerk E.R. Smith -- assistants. Volume VI. Magnetical and meteorological observation under the direction of Lieut. J.M. Gillis, LL.D. Superintendent