129 



values of its age; in tlic first instance this would cause a divergence 

 in the negative direction, and in the second in the positive. 



In the years 1892 — 94 this divergence seems to show itself, 

 and I therefore considered it desirable to introduce for tiiese years 

 a separate correction of -["O-.OG for Dl = 3, 4, 5, 6 and one of 

 - — 0^05 for Dt =r 23, 24, 25, 26; after applying tiiese corrections 

 the mean deviation for each limb was determined afresh. For the 

 years 1895 — 1902 Prof. Bakhuyzen rejected the observations for 

 Dt = 4 and 26, and applied no further separate corrections. The 

 years 1903—09 do not show these particular divergencies so con- 

 spiciiouslj' and for these I thought it advisable not to apply any 

 separate corrections for a dependence on Dt. The years calculated 

 later, 1890 and 1910, have been brought into connection with the 

 others as well as possible. The correction for the observed limb for 

 1890 is deduced from 1890—94, and that for 1910 from 1903- 10. 



I now give the differences between the results from the two limbs. 

 Limb II — Limb I, computed for each year, after the al)Ove mentioned 

 corrections had been applied. 



With one exception, these differences for the different years agree 

 fairly well with one another. 



After the corrections for the errors of observation of the limbs 

 liad been applied, a yearly mean was formed for each instrument, 

 both for the observations of the limbs and of the crater, and further 

 corrections were added to bring each class of observations into 

 agreement with the total mean. 



The total corrections were finally : 



1892—94 



1895—99 

 1900—02 

 1903—09 



After the above corrections had been applied, the observations 



9 

 Pjoceedings Royal Acad. Amsterdam. Vol. XVI. 



