Table 44 

 CAPILLARY CORRECTION FOR MERCURIAL BAROMETERS 1 



135 



Table 44 is adopted from Glazebrook 2 and gives the depression of the top of the meniscus of 

 the mercury column in barometer and other glass tubes, based on a surface tension of mercury, 

 in vacuo, in contact with glass of 0.444 gram per centimeter. It should be noted that little 

 information is available concerning the surface tension of mercury in the average barometer 

 tube. Its value is likely to differ from the value given, owing to impurities in the mercury and 

 variations in the composition and cleanliness of the glass. 



Height 

 of 



Bore of tube — millimeters 



10 12 14 16 18 20 25 30 



ram. mm. mm. mm. mm. 



mm. mm. mm. 



1.3 



2.5 

 3.5 

 4.4 

 5.2 



0.5 

 1.1 

 1.6 

 2.1 

 2.5 



0.3 

 0.6 

 0.8 

 1.1 

 1.4 



0.18 

 0.36 

 0.54 

 0.73 

 0.90 



0.11 

 0.23 

 0.35 

 0.47 

 0.59 



0.08 

 0.16 

 0.24 

 0.33 

 0.41 



0.06 

 0.12 

 0.18 

 0.24 

 0.30 



0.05 

 0.09 

 0.14 

 0.18 

 0.23 



0.03 

 0.06 

 0.09 

 0.12 

 0.15 



0.02 

 0.03 

 0.05 

 0.07 

 0.08 



0.01 

 0.02 

 0.03 

 0.04 

 0.05 



0.01 

 0.01 

 0.02 

 0.02 

 0.03 



0.01 

 0.01 

 0.02 

 0.02 



0.01 

 0.01 

 0.01 

 0.02 



0.01 

 0.01 



0.1 

 0.2 

 0.3 

 0.4 

 0.5 



0.6 

 0.7 

 0.8 

 0.9 

 1.0 



1.1 

 1.2 

 1.3 



1.4 

 1.5 



1.6 

 1.7 

 1.8 

 1.9 

 2.0 



* In the practice of most meteorological services, including the U. S. Weather Bureau, the capillary correction 

 is included in the corrections furnished with the barometer as determined by comparison with a "standard" 

 barometer. The corrections given in Table 44 should not be applied in such cases. 



3 Glazebrook, R., Dictionary of applied physics, vol. 3, p. 159, Macmillan and Co., Ltd., London, 1923. 



5.9 2.9 1.7 1.06 0.71 0.48 0.35 0.27 0.18 0.10 0.06 0.04 0.03 0.02 0.01 



3.2 1.9 1.20 0.81 0.56 0.41 0.31 0.21 0.11 0.07 0.04 0.03 0.02 0.01 



3.4 2.1 1.34 0.91 0.63 0.46 0.35 0.24 0.13 0.08 0.05 0.04 0.02 0.01 



3.6 2.2 1.45 0.99 0.70 0.51 0.38 0.27 0.15 0.09 0.06 0.04 0.03 0.01 0.01 



3.7 2.4 1.55 1.08 0.76 0.55 0.41 0.30 0.16 0.10 0.06 0.04 0.03 0.02 0.01 



2.5 1.66 1.15 0.81 0.59 0.44 0.33 0.18 0.10 0.07 0.05 0.03 0.02 0.01 



2.6 1.76 1.21 0.86 0.63 0.47 0.35 0.20 0.11 0.07 0.05 0.04 0.02 0.01 



1.26 0.91 0.67 0.50 0.37 0.21 0.12 0.08 0.06 0.04 0.02 0.01 



1.30 0.96 0.70 0.53 0.40 0.22 0.13 0.09 0.06 0.04 0.02 0.01 



1.34 1.00 0.74 0.55 0.42 0.24 0.14 0.09 0.07 0.05 0.02 0.01 



SMITHSONIAN METEOROLOGICAL TABLES 



