THE SOCIETY'S GARDEN AT CHISWICK. 



103 



In July, 1840, the ground thermometers were employed for 

 the purpose of experiments which were being made respecting 

 the soil in the beil of the great conservatory. In the autumn of 

 1843, after having been several months replaced in the arbore- 

 tum, they were accidentally broken, and the observations were 

 interrupted till the commencement of 1844. 



