the Heights of Ben-Lomond, ^c, 125 



ved at the top shortly after I had set up the barometer, and 

 were desirous to know the use of my apparatus, which, of course, 

 it was necessary to explain, it was thought proper to reject the 

 observations made during that interval, and retain those only 

 that were made between twelve and one o'clock, during which 

 the barometer was almost stationary. 



II. — Observations made with Barometer B, by Mr John Adie, at 

 RoTvardinnan, near the Base of the Mountain, and 2 feet above 

 the surface of the Lake, estimated at 32 feet above the Sea at Ihim- 

 barton, after rejecting those previous to \2 o'clock. 



HI. — Observations made with Barometer C, by Mr Thomas Hen- 

 derson, at the Calton-Hill, Edinburgh. Height of Cistern 355 

 feet above the Sea at Leith. 



Calculations of the Height of Ben-Lomond above the Sea, from the 

 preceding Observations. 



Let B denote the height of the mercury in the barometer at 

 the lower station, and h that at the higher. Then, according to 

 bur formula, in which t is the temperature of the attached ther- 

 mometer, t the temperature of the mr, and d that of the dew 

 point at the lower station, andy* the corresponding elasticity of 

 aqueous vapour, also t', t', cf,^*, the same at the higher, the 



