NO. 8.] PENDULUM OBSERVATIONS. 9 
watch is given for 24 hrs., the correction, u, is 586 units in the 7th decimal 
place for every second. The correction for the amplitude, a, is 
a= 7s, 
where a is the observed amplitude, and / the distance in millimetres between 
the coincidence apparatus and the pendulum mirror, while S is the period of 
the pendulum, Each division on the scale is equal to 3 mm. 
For the thermometers before the journey, we have, according to the 
above, 
Thermometer 20 ¢° C. = 1°863 (reading — 3°41) (in 1892) 
— 23 ¢° C. = 1:988 (reading — 2°66) 
— 24 ¢° C. = 1903 (reading — 2°16); 
during and after the expedition, 
Thermometer 20 ¢° C. = 1°863 (reading — 3:41) — 0°.09 (in 1893 and 
subsequently) 
23 ¢° C. = 1:988 (reading — 2°66) — 0°.25 
— 24 ¢° C. = 1:903 (reading — 2°16) — 0°.375. 
