JET. 30-40.] COUNT RUMFORD. 37 



roads, by employing the soldiery in repairing them and 

 preserving order and public tranquillity on them. 



A new English Garden was formed, beginning upon 

 the ramparts of the town. It was nearly six English 

 miles in circumference. Within the Garden was a 

 fine and very valuable farm, with thirty of the finest cows 

 procured from Switzerland, Flanders, the Tyrol, and 

 other places. There was a public coffee-house in the 

 middle of the Garden for refreshment and public 

 resort. 



The scientific work which Sir B. Thompson did 

 whilst in the service of the Elector of Bavaria between 

 1783 and 1794, shows his energy and originality, his 

 accuracy and his depth. 



When at Mannheim in July 1785 he made experi- 

 ments in the presence of Professor Hemmer, of the 

 Electoral Academy of Sciences of Mannheim, on the 

 propagation of heat through various substances ; on the 

 increased difficulty of conduction of heat through the 

 torricellian vacuum ; on the effect of humidity in 

 increasing the conducting power of the air ; and on the 

 effect of air of different degrees of density. The Duke 

 ordered the meteorological instrument maker to the 

 academy at Mannheim to come to Munich, and to 

 spare neither labour nor expense in providing the com- 

 plete apparatus necessary for the experiments. 



These experiments, on the relative conducting 

 powers of mercury, water, air, and a torricellian 

 vacuum, were read to the Eoyal Society, March 9, 

 1786. 



He then proceeded to make experiments on the rela- 



