NEW SELF-REGISTERING BAROMETER. 505 



the values of the markings are indicated by the vernier fixed at c; e is the milled 

 nut attached to the screw which guides the pointer /to the various lines on the 

 cylinder. 



When the barometer is first put in action, the scale is adjusted to its proper 

 height by observations made at the same hours of a standard barometer. Should 

 the register be found too high, the fixed pivot b is loosened and screwed out until 

 the vernier and scale correspond to the height observed at that hour on the stand- 

 ard barometer, after which it is fixed, and the other observations will be found 

 to correspond within the usual limits of discrepancies in barometric observations. 



The following are the observations registered since the barometer was first 

 completed, June 22. 1843. They were made in Princes Street, Edinburgh, at the 

 height of 211 feet above the mean level of the sea. 



All the observations are comparable with those at Greenwich and the Royal 

 Society of London, as the clock is kept at Greenwich Mean Time. 



HOURLY REGISTER. 



