In comparing the previous tables, it may be well to premise the 

 remark, that this city is situated in north latitude 42^39 and west 



The following schedule (table XVII.) brings together the re- 

 spective observations, so far as they can be compared with each 

 other. As I have already explained the cause of the partial va- 

 cancies in the years in 1830, '31 and '32, I may here state that ta- 

 ble XVIII. exhibits the variations noticed in pursuing the double 

 sets of observations made in 1826, '27, '28 and '29. It wiU be 

 seen that on the annual mean they hardly differ half a degree. In- 

 deed during three of the years the difference is less. 



