1904.] Cotton by Water and ~by Water Vapour. 237 



Experimental Results. 



In what follows and in the curve diagrams 



t is the time measured in minutes from the moment of immersion of 

 the cotton-covered thermometer ; 



is the temperature of the same at the moment t, in degrees 

 Centigrade, its own initial temperature, which is the constant tempera- 

 ture of its environment, being taken as zero ; 



<j> is the maximum value attained by in the course of the 

 experiment ; 



T is the value of t at which = < 



m is the weight of water vapour, in milligrammes, absorbed in the 

 time t j 



p is the weight of any water vapour, also in milligrammes, absorbed 

 by the cotton prior to the commencement of the experiment ; 



A is the area, determined by planimeter, bounded by the curve, 

 the, t axis, and a vertical ordinate corresponding to the time t; 



or A = \0dt. 



Jo 



The terms " water immersion " and " saturated air immersion " have 

 already been fully explained. " Previous moisture " serves to designate 

 that of which the quantity is p. The term " dry curve " is used to 

 distinguish one belonging to an experiment in which the cotton is 

 dry to start with from those which show the effect of previous 

 moisture. 



It is unnecessary to reproduce here the numerous t and readings 

 of the experiments. They are therefore summarised in the following 

 tables, giving the values of T and <, the final values of t and 0, and 

 the corresponding values of A and m (where determined), and the value 

 of p in cases where previous moisture was present. In Tables III and 

 V calculated values of m are given also. The mode of calculating m 

 from A and will be explained later. Some of the curves are shown 

 in the diagrams, and references to these are given in the tables. 



The experiments which formed Series I were of a purely preliminary 

 character, and are therefore omitted. Those of Series II were, as 

 already explained, less accurate than later ones ; but they are correct 

 enough for their purpose, for they show by comparison with Series III 

 ^he general similarity of the temperature change produced by water 

 immersion and by saturated air immersion, both with and without 

 previous moisture. Series III also gave information as to the progress 

 of absorption during exposure to saturated air ; and the main purpose 

 of Series IV and Series V was to trace this more fully in connection 

 with the temperature change. They also supplied some evidence as to 

 the influence of bath temperature and weight of cotton. Finally water 

 immersion tests, carried out in conjunction with Series IV and V, gave 



