London Horticultural Society and Garden. 



43 



It was stated that the mean temperature of 1837, was 48-52° Fahr., while 

 the mean of ten preceding years, as registered at the garden, was 50*62°, and 

 consequently the year 1837 was about 2° colder than usual, notwithstanding 

 the absence of severe weather in January, and the extraordinary mildness of 

 December. The lowness of temperature occurred in the growing part of the 

 season, and more especially in March, April, and May. The season was not 

 only colder, but much drier: for the whole amount of rain was only 19-88 in., 

 which is about 4 in. below the average quantity that falls round London. 



Mr. Thompson communicated a memorandum concerning the temperature 

 of the earth for the seven last months of 1837; as indicated by two geother- 

 mometers buried in the soil, one a foot and the other 2 ft. below the surface, 

 and compared with a common thermometer suspended in the air 3 ft. above 

 them. 



The monthly results are expressed in the following table: — 





MeanTemperature of Earth, 



indicated by the two 



Geothermometers. 



Mean Temperature of Air 



indicated by a common 



Thermometer 3 ft. above 



ground. 



June 



July 



August 



September 



October 



November 



December 



59-01° 



64-19 



63-38 



57-92 



53-6 



44-6 



42-74 



60-08° 



63-16 



62-53 



55-68 



50 



40-22 



4138 



Mean 



55-06 



53-29 



From the above, it appears that the difference between the terrestrial tempe- 

 rature at the above depths (1 and 2 ft.), and that of the atmosphere near 

 the surface of the earth, is 1 -^ Fahr. But as the ground is comparatively 

 warmer than the atmosphere in the autumn, and colder in spring, it may be 

 inferred that the mean temperature of the earth, a little below the surface, 

 agrees very closely with that of the atmosphere, taking the average of the 

 whole year into account. The average of the 1 ft. geothermometer was 

 55-01°, that of the 2 ft. geothermometer was 55-13°. The difference being only 

 about J_ of a degree. The highest temperature indicated by the 1 ft. 

 geothermometer was 96°, and by the 2 ft. instrument 66°. This occurred 

 about the 28th of July ■ but, on the whole, Jul}' and August maintained 

 nearly an equal terrestrial temperature. The difference between these months 

 and December was upwards of 20°. 



The following objects were exhibited: — From Mrs. Lawrence, F.H.S., a 

 small collection of plants, among which a beautiful specimen of Pavetta 

 caffra was conspicuous for its numerous close cymes of snow-white flowers. 

 From George Barker, Esq., F.H.S., a flowering spike of the sweet-scented 

 Epidendrum primulinum, a new green-flowered orchidaceous plant which 

 he had introduced from Cuba. From Messrs. Lowe and Co., of Clapton, 

 plants in flower of the rare Chysis aurea, the beautiful Statice arborea, 

 and Clematis caerulea. It was stated by Mr. Lowe that the latter, which 

 is one of the handsomest species of Clematis (see Botanical Register, 

 vol. xxiii. t. 1955.), proved perfectly hardy during the late winter. From 

 W. Bromley, Esq., F.H.S., a small collection of green-house plants, among 

 which was a flowering specimen of Banksia speciosa. From Mr. Dennis, 

 nurseryman, Chelsea, a collection of Pelargoniums. From Mr. Dunsford, 

 gardener to Baron Dimsdale, specimens of Coryanthes speciosa, an extremely 

 curious orchidaceous plant, and of Combretum purpureum. From the 



