466 
With this telescope, which I received in July 1909 and to which 
a ring-micrometer was added, I then continued my observations, 
principally of occultations and of phenomena of the satellites of 
Jupiter, while I succeeded in 1910 in obtaining some observations of 
Harry’s comet. All this time, however, I had constant trouble from the 
weather conditions, as the sky usually became clouded over in the 
evening, and moreover in the years which followed, my astronomical 
work was more and more interrupted by my other occupations, so 
that at the end of 1910 1 was obliged to temporarily close my 
observations of occultations. In the last three years [| had been able 
to obtain 24 observations, although almost exclusively of disappear- 
ances. Of these observations 10 concerned known stars, for the 
oceultations of which I could make the necessary preparations, while 
14 were of unknown stars, which had to be first identified by 
diagrams which I made for ‘the purpose and had subsequently to be 
accurately observed in the meridian. 
The occultations of the known stars | soon afterwards calculated 
and made use of for the determination of the longitude. For these 
calculations 1 used both Bressers method and an approximation method 
given by OvpreMaNs and refined still more by E. F. vaN DE SANDE 
BAKHUYZEN, which in most cases yielded sufficiently accurate results. 
Of course at the moment I could only make use of approximate 
elements, especially as regards the places of the moon, and although 
that might now be corrected, it appears to me preferable to wait 
with my tinal calculations, until | have at my disposal sufficiently 
accurate positions for all the stars observed. 
For only 7 observations | made calculations with provisionally 
corrected elements, in which (1) I introduced a general correction 
to the R.A. of the moon of + 040, and corrected the declination 
in accordance with this, (2) I assumed the lunar parallax according 
to Newcoms, and (3) for the semidiameter of the moon I used the 
value 15'32"68, which was deduced by Prof. BAKHUYZEN from occul- 
tations and heliometer-observations. 
Thus I obtained as results for the longitude of my place of observation 
1908 June 16 PXIX 369 Reapp. — 48m 3152 
Sept. 30 = w Ophiuchi Disapp. - 25.0 
Nov. 6 yp Piscium x Sees er 
1909 March 28 s Geminorum ,, 30.8 
1910 March16 v, Tauri i 30.1 
3 20 rant of 30.0 
May 20 — /, Virginis . 28.7 
