The two standards, the cubic inch and the cubic decimetre, may not be strictly comparable owing to a difference in the normal temperature (**Centigrade** and Fahrenheit scales) of the two units of extension, the metre and the yard.

This unit is taken as being 4.180 joules per gramme-degree-**centigrade** on the scale of the platinum thermometer, corrected to the absolute scale as explained in the article Thermometry, Which Has Been Shown To Be Practically Equivalent To The Hydrogen Scale.

Adopting the **centigrade** scale, this gives 1390.846 foot-pounds.

System of expression in ergs per gramme-degree-**centigrade**, or " calorie," is the most appropriate, as being independent of the value of gravity.

The following table contains the most probable values for a few of these points which have been determined with the greatest care or frequency: Table of Boiling-Points at Atmospheric Pressure on **Centigrade** Scale Alphabetical Index of Symbols Empirical constants in formulae; section 14.

Relation Of Surface-Tension To Temperature It appears from the experiments of Brunner and of Wolf on the ascent of water in tubes that at the temperature t° **centigrade** T =75.20 (I -0.00187t) (Brunner); =76 08 (i-o o02t-Po ooOo0415t 2), for a tube .02346cm.diameter (Wolf); = 77.34(1 -o oo181t), for a tube 03098 cm.

The formulae show the number of cubic centimetres of gas absorbed by i litre of sea-water; t indicates the temperature in degrees **centigrade** and CI the salinity as shown by the amount of chlorine per mille: 02 = 10.291 - 0 .

Employing this method, Callendar finds S = 0.497 for steam at one atmosphere Temperature **Centigrade** FIG.