14 REPORT — 1839. 



In reply to a question from the President, Mr. Lloyd briefly explained 

 to the Section the arrangement of the portable observatory, adopted by 

 Captain J. Ross, in his preparations for the Antarctic expedition. It is 

 so constructed as to form, either three small separate rooms, or one 

 large one ; the former arrangement being desirable at places where 

 the dip is nearly 90°, and where, consequently, the horizontal directive 

 force is very small, and the disturbing action of the magnets on one 

 another, relatively great. The parts are put together with copper 

 fastenings ; and the whole is so arranged, as to occupy a very small 

 bulk when in pieces, and to be capable of being put together with 

 quickness and security. 



Meteorological Observations made at Great Malvern during the years 

 1835, 1836, 1837, and 1838. By Mr. Addison. 



In these tables, the mean results for every month, and for the vari- 

 ous seasons, and for each year, have been computed. Great Malvern, 

 in Worcestershire, has an elevation of about 500 feet. Great diifer- 

 ences of temperature have been observed within short distances — the 

 lower localities being frequently very much colder than the more elevated 

 ones. Thus on three or four occasions drops of rain have fallen, with 

 the thermometer in the vale at 24°. The dew-point is subject to greater 

 variations, and frequently falls to a much lower point in the higher 

 situations, except when the temperatures are very different ; it then 

 appears, that the dew-point is frequently very low in the cold, misty, 

 foggy air of the valley. From these tables it appears that the mean 

 temperature of Malvern is 4;7'7 ; the highest annual mean is 49*1, in 

 1835 ; and the lowest ^6' 5, in 1838 ; being a diiference of 2*5 between 

 these two years. The mean barometer is 29*386 ; and the mean dew 

 point, at 9 a.m., 43'7. When the mean temperature of the year is 

 higher, the mean dew-point also is higher ; thus, in 1835, mean tempe- 

 rature, 49*1 — mean dew-point, 44*7 ; in 1838, mean temperature, 46*5 

 — mean dew-point, 42*4. In 1837, the lowest temperature of the year 

 occurred in the night of the 25th of March. The maximum of the 

 barometer, in three out of the four above-mentioned years, occurred in 

 the first week of January. The minimum of the barometer, in three 

 out of four years, occurred in November. The range of temperature 

 during the four years, from 9° on the 20th of January 1838, to 84° on 

 the of 5th July 1836, is 75°. The range of the barometer, from 28*010, 

 on the 29th of November 1838, to 30*228, on the 14th of October 1837, 

 is 2*2 inches. The aurora borealis was observed in November, 1835; 

 in May, 1836 ; in February, March, April, August, October, and 

 November, 1837; and in September, 1838. A remarkable noise was 

 heard at 4 p.m. on the 4th of August, 1835, like a loud clap of thunder, 

 the air at the time being quite free from cloud, and the sun hot and 

 brilliant. Very high winds, with the air at the dew-point, occasion a 

 large evaporation. 



