1919.] New Zealand Institute Science Congress. 319 
Very full data for the observation of the eclipse were published by 
the Nautical Almanac, and some months before the eclipse Professor 
R. H. Tucker observed the position of the moon with the meridian circle 
of the Lick Observatory and found it very slightly ahead—about 20 s. of 
the predicted place in its orbit. The total phase of the eclipse actually 
occurred 3 s. later than the Lick Observatory prediction—that is, 17 s. of 
time in advance of the Nautical Almanac prediction. 
The computed duration of totality was 1 m. 57-3 s., while the observed 
duration was 1 m. 57*4 s. Attempts were made to test the Einstein and 
relativity effects by photographing the stars near the sun, when stars 
fainter than the eighth magnitude were recorded on the plates. It is hoped 
that evidence may be obtained of the effect of the sun on rays of light; 
and by comparing photographs taken of the same region when the sun is 
not there interesting results are expected. 
The Lick Observatory had exceptionally good luck at this eclipse : 
the whole observing programme was carried out with complete success, 
and the sky, which had been completely cloudy all day, cleared up less 
than 1 m. before totality began, and remained cleared until a few seconds 
after the end • of totality. The small region of unclouded sky containing 
the totally eclipsed sun seemed to be quite clear, and was the bluest sky 
seen by the expedition. Equally important, the atmosphere during 
totality was very tranquil; the seeing was excellent. 
Dr. Campbell lays very strong stress on the great importance in future 
eclipse expeditions of studying the weather conditions at the time of day 
totality takes place, as many local peculiarities may be overlooked if the 
weather observations are taken at other times of the day. He urges that 
these observations should be taken for some years in advance of each 
observable eclipse. It is hoped that for the eclipse in September, 1922, 
across Australia such observations will be undertaken, along the line of 
totality, during the month of September in 1919, 1920, and 1921. 
Determination of the Position of the Moon by Photography, by C. E. 
Adams. 
Abstract. 
An exhibit was made of photographs, taken at the Lick Observatory, 
of the moon and surrounding stars, to determine with great accuracy the 
position of the moon. This work was undertaken to enable Professor 
R. W. Brown, the eminent mathematical astronomer at Yale, to check his 
new tables of the moon. On the original plates stars as faint as the tenth 
magnitude were successfully photographed at full moon. The exposures 
were usually 4 minutes on the stars, then J second on the moon, and then 
another 4 minutes on the stars. The excellent star-images secured speak 
well of the Crossley reflector telescope, which was driven without any 
guiding, and the photographs prove that the position of the moon and 
terrestrial longitude can be determined with high precision. 
The Almucantar Method of Observations for the Determination of Time 
and Latitude, by C. E. Adams. 
A Nomogram for Transit Instrument Star Factors, by C. E. Adams. 
