METHODS EMPLOYED IN CALIBRATION OF MERCURIAL THERMOMETERS. 197 



means of Table XLVIII., and the values of I, the corrections for the 

 npper points of the first three additional measni-es of Thread I. are 

 found. By this means the curve given by Thread I. is prolonged, and 

 the operation of completing the second mean curve is carried out in a 

 manner similar to that adojited in the first approximation. 



Table XLVIII. 

 ■L - L + <p (it). In terms of 0°-001. 



Table XLIX. 



Corrections for Upper Points of Additional Threads j^^tted down in Curves in fg. 4, 



Plate III. 



The curve must now be made to pass through the standard points. 

 This operation is performed as in the previous example, the formula 

 in this case beino: 



0-230 - 



0-215 f ^ ^ / N ^ n oQn 0-215 



s a; + ^ (a;) + 0-230 — — x 



40 



40 



} 



It is unnecessary to give details, 

 points are : — 



Table L, 



The correction for the initial 



