418 MR. J. H. BRINKWORTH ON THE SPECIFIC HEAT OF STEAM AT 



thereby introduced. The apparent values of the specific heat obtained with 

 various amounts of gauze and with the above arrangement of apparatus ranged 

 about 1'95, gradually increasing as more gauze discs were inserted. 



(d) Further experiments with gauze mixing were carried out with the calorimeter 

 and jacket, arranged as in fig. 7, and with the enclosed thermometer used in the 

 earlier and in all the later experiments. 



That part of the thermometer sheath surrounding the ivory bulb of the platinum 

 thermometer carried gauze discs, a variable number of similar discs being interposed 

 between the end of the heating coil and the end of the thermometer tube. With 

 4'5 cm. length of discs on the thermometer tube, and a length of 7 cm. of the total 

 distance between the end of the thermometer and the heating coil filled with similar 

 discs, the value of S c calculated from the experimental observations increased 

 (approximately proportionately) with the actual distance between the heating coil 

 and the thermometer. Again, with a distance of about 14 cm. between heating coil 

 and thermometer, the calculated value of the specific heat increased with the length 

 of tube filled with gauze, the latter variation being from 1'965 with 4'7 cm. of gauze 

 to T990 with 10 cm. of gauze. These results show that, in order to mix the steam 

 thoroughly by means of gauze discs, a much greater distance must exist between the 

 thermometer and heating coil than was possible in this arrangement without having 

 a great length of the thermometer-stem exposed. Further experiments on gauze 

 mixing were not made for the above reason, and also because, in order to change 

 either the position of the thermometer or the amount of gauze, it was necessary to 

 dismantle the calorimeter. 



The Final Experiments. 



These may conveniently be divided into two groups : one consisting ot the 

 experiments made with the non-vacuum jacketed calorimeter, the other group 

 including all the experiments performed with the different types of vacuum vessel. 

 Abridged tables of the experimental measurements are to be found below (p. 425). 

 Complete records of all the observations are preserved in the Archives. 



Group 1. Experiments with the NoTi-vacuum Jacketed Calorimeter. Fig. 7 shows 

 the general arrangement of the calorimetric apparatus during the course of these 

 experiments. The thermometer was fixed eccentrically in the spiral constructed of 

 discs of copper foil. The conditions under which the experiments in this group were 

 made were varied considerably. The group itself consists of four series of experiments 

 which only differ in that the heat-loss has been progressively augmented by increasing 

 the distance between the heating coil and the thermometer by sliding the latter in its 

 enclosing sheath. In each series three flows were used, and at least two different 

 values of the rise of temperature. 



Group 2. Experiments with Vacuum-jacketed Calorimeters. The general arrange- 

 ment was as in the last group of experiments and as indicated in figs. 7 and 8. 



