which determine the Indications during Absence. 347 



about three feet in height, having a projection at the base, in 

 the form of a pedestal, would form not only an elegant but a 

 very complete and highly useful barometrical apparatus. The 

 column being hollow not only lessens the weight, but admits of 

 the timepiece and connecting mechanism being entirely conceal- 

 ed within it 



The barometer, however, may also be arranged on a flat sur- 

 face * without producing any thing of an unwieldy appearance, 

 and the adaptation of the mechanism for shutting one of the 

 stop-cocks each hour in succession, is not thereby rendered more 

 difficult. 



See Fig. 3. Plate XIII. 



