822 
which have been found for An and Ad, especially the negative 
value of the mean A,r. This latter is equivalent to a secular accele- 
ration of which the coefficient would, with the above value of gq, 
become 307". This, of course, is entirely inadmissible and conse- 
quently it is not possible to consider the value of 4,r as real unless 
we take for q such a smail value that the whole effect becomes 
entirely negligible *). The partial agreement of 2, with the empirical 
terms of long period can therefore not be considered as a proof for 
the existence of an absorption of gravitation. 
We now come to the comparison with the observations of the 
periodic part of our computed perturbation. This comparison was 
only carried out for the time after 1829. From 1847 to 1912 [ had 
the advantage of being able to make use of a new and careful 
reduction of the Greenwich meridian cbservations which Prof. E. 
F. VAN DE SANDE BAKHUYZEN most kindly placed at my disposal. 
Prof: BAKHUYZEN applied to the meridian observations the correction 
for the difference of right ascension of the moon between the epochs 
of true and of tabular meridian passage, for those years in which 
this correction had not yet been applied at Greenwich. Then the 
systematic corrections, which in his former reduction (These Pro- 
ceedings, Jan. 1912), were taken constant over the whole interval 
from 1847 to 1910, were derived anew. The following are the syste- 
matie corrections finally adopted by Prof. Bakuvuyzen for the obser- 
vations of the limb: 
1847—48 49—57 58—68 69—78 79—98 1899—1911 
0".00 —1".61 —O0"83 —O0".93 —0".62 +0".39 
For the observations of the crater Mösting A the correction was 
derived in two different ways, which gave —0".22 and + 0.34 
respectively. The adopted correction is 0".00. Prof. BAKHUYzEN then 
formed the means of the meridian observations of the limb, of the 
crater and the occultations, the latter being taken from Neéwcoms’s 
paper, but corrected by -+ 0".18, for reasons explained in his 
paper of Dec. 1911. The corrected results of the meridian observations 
and the means thus derived are given in Table VII in the second 
part of this paper. From these means I then subtracted the theoretical 
corrections given by BarrerMann and quoted above. The resulting 
corrected means which are thus the excesses of the longitude of. 
the moon over the pure gravitational value, diminished by Nuwcomp’s 
great fluctuation, were plotted and a smooth curve was drawn through 
1) In my former investigation I was led to a similar conclusion (see “The obser- 
vatory’ Nov. 1912 page 892). 
