218 
The N.Z. Journal of Science and Technology, 
[Nov. 
The calculation is then performed as follows :— 
u 
X 
X—u 
V 
y • 
y—v 
h + 2 h. 29 m. 
+ 45 
+ •27 
— •18 
h + 3 h. 29 m. 
+ •59 
+ •81 
+ •22 
•52 
•58 
•06 
— •58 
— 42 
+ •16 
When x — u is negative it shows that the Moon is west of the star ; when 
y—v is negative the Moon is south of the star. The rest of the calculation 
is effected by plotting these two positions, as shown on the diagram, and 
drawing the line M / -M // through them to represent the apparent path 
of the Moon past the star. The circle is drawn round the place of the 
star with radius 0-272, and it must cut the line M y M„ at the times of 
the star’s disappearance and reappearance. These are found by measure¬ 
ment of the diagram to be Greenwich times 20 h. 48 m. and 22 h. 1 m., 
corresponding to New Zealand mean time 8 h. 18 m. and 9 h. 31 m. on 
November 1, 
south 
Occultation of 16 b Aquarii at Wellington, November 1, 1919. 
Table A. 
For finding what fraction of an hour the apparent conjunction of Moon 
and star will be accelerated if the hour-angle at true conjunction is east, 
or, conversely, how long it will be retarded if the hour-angle is west. 
The table is to be entered with the hour-angle at the side and the 
Besselian element x at the top. 
h 
•52 
•57 
•62 
1 hour 
•58 
•51 
•45 
2 hours 
1-03 
•92 
•82 
3 hours 
1-30 
M8 
1-05 
4 hours 
143 
1-30 
148 
