44 



ROVAL HORTICULTURAL SOCIETT. 



X. Observations by Mr. Thompson on the Temperature in the 

 Large Conservatory at Chiswick, comparatively with the 

 external Air in shade and against South-aspect wall, as sug- 

 gested by G-aylard Had wen, Esq., 1\K.H.S. (Journ. Hort. 

 Soc. n. s. vol. i. p. 193). - 



Tiie large conservatory at Chiswick having been converted into a 

 vinery, and having a large space and surface of glass exposed to 

 the light, the crop of grapes was thought worthy of particular ob- 

 servation, in accordance with Mr. Had wen' 8 suggestions, as re- 

 gards the circumstances of temperature under which they were 

 produced. The bunches and berries were large and well coloured, 

 although brought forward chiefly by the sun's rays, with but very 

 little aid from artificial heat. 



May. — In this month the average maximum temperature of the 

 external air in the shade was G3°, and the minimum 35°. Con- 

 servatory maximum 79°, minimum 51°. Against the south wall 

 maximum 77°, minimum 41°. It thus appears that the tempera- 

 ture of the south wall was 14° higher than the open air, and 2° 

 lower than the conservatory. In the latter fire-heat was supplied 

 at night, and the weather being cold, a little occasionally in the 

 day throughout the month. By the 7th the vines were showing 

 fruit, mostly two bunches on each shoot, and the shoots were \\ 

 to 2 feet long, about the 11th the shoots were stopped, generally 

 at one joint beyond the fruit, others at two joints, according as 

 there was space for the extension of the shoots. By the end of 

 the month the vines were mostly in flower on the south side of 

 the house ; those on the north side were about two days later. 



June. — The maximum temperature of the external air in the 

 shade was 75°, minimum 44°. Conservatory maximum 83°, mini- 

 mum 58°. The south wall maximum 87°, minimum 52°, so that 

 the south wall maximum was 4° higher than that of the conserva- 

 tory, whilst the minimum of the latter was 6° higher than the 

 south wall. Very little fire-heat was supplied to the conservatory, 

 except occasionally at night. By the 4th the fruit was mostly set, 

 and the vines were stopped a second time, and by the 8th the vines 

 were out of flower, the berries were being thinned, and many 

 bunches were thinned off at the same time. 



July. — The mean maximum of external air in shade was 74°, 

 minimum 46°. Conservatory maximum 80°, minimum 5S°. South 

 wall maximum 89°, minimum 53. It appears that the maximum 



