Pyschronictrlr For in ula. 1 57 



Method of Reduction. 



In dealing with the former series of observations, the individual 

 values of the coTis'tant A were determined from the formula 



;c = /- AB(/-/'), 



taking the vapour-pressures x and f from Broch's tables. The arith- 

 metic mean of these values was taken to be the most probable, or most 



