340 MR. E. H. GRIFFITHS ON THE LATENT 
Hence 6, = 29°°913 and R, + 7 = 10°3513 true ohms. 
therefore, when 6, = 80°:000 Ips oP SLO BHI 5, % op 
The values of R vr at about 30° were also ascertained on other dates and were 
1 ’ 
as follows :-— 







Date. | - Temperature. Ry + 7. R, + 7 at 30°. 
ea ne 
September]5 . .. . | 30°003 10°3516 10°3516 
October 5. er ae 30:245 10°3522 10:3516 
5 0s | 30-044 10-3518 10-3517 
elite | 29-913 10:3513 10°3515 

I think it unnecessary to multiply examples at cther temperatures, the above will 
show the order of accuracy. 
From the above values, the value of 7 (= ‘0034, see p. 296) must be subtracted in 
each case to get the value R,, given in Table VIII., p. 297. 
DeEscRIPTION OF PuaAtes 4, 5, and 6. 
PLATE 4. 
The lower figure is a vertical section of the steel chamber and tank. The spaces 
filled with mercury are printed in black. The tube at D communicated 
with the regulating apparatus. 
The upper figure is a plan of the lid. 
PLATE 5. 
Fig. 1 is a vertical section of the calorimeter. When gas was driven through the 
apparatus it entered at f, passed into the bottom of the silver flask F at G 
and left it near the roof at d. It descended to the bottom of the 18 ft. 
silver coil (sections of which are shown by the small circles at C,), then 
ascended a gentle slope and finally left the calorimeter by the tube e. 
Although in different planes from the section, the position of the platinum 
thermometer is indicated as well as S, the bottom of the stirrer. A “dropper” 
is shown in position in the tube h. 
Fig. 2 is a horizontal section across the calorimeter at AB in fig. 1. 
Fig. 3 is a plan of the lid. 
The stirring shaft passed through $8, the platinum thermometer down T, 
and ‘the tube h’ established communication with the flask F (fig. 1). The 
ends of the silver spiral are shown at c and /- 
