221 



shore, and on. board Her Majesty's ships ' Erebus' and ' Terror,' 

 under the direction of Captain James Clark Ross, R.N., together 

 with a Series of Observations made on the temperature and specific 

 gravity of the ocean at various depths, and at the surface, namely, 



" Observations of the magnetic intensity on shore, and on board 

 H.M.S. Erebus, with needle F. 1. 



" Magnetic dip observations on shore, and on board H.M.S. Ere- 

 bus, with needle F. 1. 



" Observations for the magnetic dip on shore, and on board H.M.S. 

 Terror. 



" Observations of the magnetic dip by needle F. C. 5. on shore, 

 and on board H.M.S. Terror. 



" Observations in magnetic intensity by needle F. C. 5. on shore, 

 and on board H.M.S. Terror." 



The whole of these observations are up to the 31st December, 

 1839. They are transmitted to the Royal Society from the Lords 

 Commissioners of the Admiralty. 



2. Postscript to Major Sabine's paper, entitled " Contributions to 

 Terrestrial Magnetism," which was read at the last meeting ; con- 

 taining an extract from a letter from Capt. James Clark Ross, com- 

 manding the Antarctic expedition, dated from St. Helena, February 

 9th, 1840 ; noticing the success which had attended the employment 

 of Mr. Fox's instrument, in observations of the magnetic dip and 

 intensity on shipboard. 



3. "A few remarks on a Rain Table and Map," drawn up by 

 Joseph Atkinson, Esq. Communicated by P. M. Roget, M.D., 

 Sec. R.S. 



The table and map which accompany this paper exhibit the ave- 

 rage annual depth of rain falHng in different places in Great 

 Britain. 



4. " Extracts from a Meteorological Journal kept at Allenheads, 

 in the county of Northumberland," by the Rev. W. Walton, F.R.S. 



The general result of these observations, which were recorded 

 twice each day, namely, at 9 a.m., and at 3 p.m., during the whole 

 of the year 1839, is, that the mean temperature taken at those times 

 was 44° 8' ; the mean height of the barometer, corrected and re- 

 duced to the temperature of 32°, was 28-401 inches, and the quan- 

 tity of rain in the year was 55"71 inches. The author subjoins se- 

 veral remarks on the conclusions deducible from an examination of 

 the tables. 



5. " Description of an Astronomical Clock invented by the late 

 Captain Henry Kater, F.R.S.," drawn up from his own memoran- 

 dums by his son Edward Kater, Esq. Communicated by Sir John 

 F. W. Herschel, Bart., V.P.R.S. 



The great object aimed at by Captain Kater in the construction of 

 the escapement of a chronometer, is to communicate equal impulses 



