370 



MR T. C. BAILLIE ON THE 



too much by something less than one-half per cent. An example of such a curve of 

 correction for cooling is given in fig. 1. 



At temperatures over 100° C. another form of heater was used. An iron tube was 

 surrounded by a conical -shaped iron chamber riveted on to it, and mercury was put in 

 the space between. This was heated by a circular gas burner, the flame of which was 

 regulated by the volume of the mercury, which, on expanding above a certain limit, cut 

 off all the gas, except what found its way through a small by -pass. The by-pass wa3 

 arranged to allow just sufficient gas through it to keep the burner lighted, and thus to 

 save the trouble of lighting the gas when the mercury had contracted sufficiently. The 

 arrangement was similar to that shown at E in fig. 2. The flame rose and fell about 

 ten times in a minute. The temperature at any one place in the heater was very 

 steady after it had been in action for an hour or two, but the temperature near the top 

 of the inner tube was 2 or 3 degrees lower than that of the hottest part. The ther- 

 mometer used for reading the temperature of the nickel in this heater was put in so 

 that the bulb touched the nickel. The nickel dropped into the calorimeter through the 

 centre of the ring burner. The inner tube of the heater was prolonged below the 

 burner. Corrections for stem exposure have been applied to the readings of the 

 thermometers. It was possible to obtain only an approximation to the stem corrections 

 on account of the manner in which the thermometers were placed, with some part of 

 their stem at unknown temperatures ; but as the correction is only 2 per cent, in the 

 greatest instance, they are probably accurate enough. 



The following tables give the data obtained in the last sets of experiments done : — 



Set I. 



Mass of nickel, . 



Mass of water in calorimeter, 



Water equivalent of calorimeter, etc., 



99-3 grammes. 

 156-7 

 3-5 















Log. Ratio Rise 



Date of 



Initial Teinp. 



Corrected Temp. 



Rise of Temp. 



Initial Temp. 



Fall of Temp. 



of Temp, of 

 Water to Fall of 



Experiment. 



of Water. 



of Mixture. 



of Water. 



of Nickel. 



of Nickel. 















Temp, of Nickel. ' 



1897 













i 



! 



July 7 



16-94 



21-87 



4-93 



99-1 



77-2 



2-8052 



1) JJ 



18-80 



23-65 



4-85 



99-2 



75-2 



2-8072 



)) M 



19-98 



24-83 



4-85 



99-3 



74-5 



2-8135 



JJ JJ 



20-88 



25-72 



4-84 



99-4 



73-7 



2-8173 i 



,. 8 



18-65 



23-54 



4-89 



99-4 



75-9 



2-8091 



>i j) 



19-60 



24-46 



4-86 



99-4 



74-9 



2-8121 



j) >> 



19-12 



23-99 



4-87 



99-4 



75-4 



2-8101 



Arithmetic 



) 













mean of ob- 



V 19-14 



24-01 



4-87 



993 



75-3 



2-8107 



served values 



f 

















Average v 



alue of specific 



heat, -104. 







