de) 
1 + 2m 34°64 (+ 0:90) 
II 34.59 (+ 0.88) 
II] 34.77 (+ 0.80) 
1V 34.70 (+ 0.78) 
I adopted the mean of the results HI and IV, viz. + 234874 
lon 
and then as final result for watch N°. 7 the mean of the results 
from (1°) the individual journeys and 2°) the whole material together 
+ 2m 34°64 
c. Watch N°. 77. 
This watch was taken on the 2°¢ journey to Mecca, but unfortunately 
it stopped between the observations of Febr. 24 and 25, as it had been 
forgotten to be wound. For a comparison of the corrections determined 
at Mecea with corrections to Jidda-time we can therefore only use 
extrapolated values . 
So we found : 
Febr. 24 + 2m 33°41 
es 36.77 
AE 35.10 
le ee 24.57 
Mean I + 2” 34:96 
eg 34.56 
me 34.51 
The first mean value was obtained by giving equal weights to 
the 4 days; for the 2ed we adopted weights inversely proportional 
to the interval of time, for which extrapolation had taken place; 
for the formation of the 3rd we moreover gave half weight to Febr. 26. 
After all it seemed best to ignore the smaller weight of the 
last-mentioned time-determination, but to take into account the 
intervals of extrapolation and I therefore adopt as final result: 
+ 2m 34556 
d. Watch N°. 80. 
This watch was taken to Mecca on the 4st and 8rd journeys. It 
did not seem advisable to immediately connect these two, which are 
separated by an interval of nearly one month. There is the same 
objection against forming the combination Me—Ji—Me. Hence we 
can only discuss two journeys Ji—Me—Ji each by itself, but then 
we meet with the difficulty that with linear interpolation the results are 
not free from the influence of a progressive variation in the daily 
