REPORT OF THE SECRETARY. 83 
tions of the earth, and had been so much impressed by the value of 
the sohar variation observations for forecasting purposes th.at they 
had arranged to receive daily telegraphic reports of the values ob- 
tained at Calama, Chile. The director of the observatory at Calama, 
Mr. Moore, had conceived a feeling that the sky conditions were not 
as favorable as perhaps might be secured in other parts of South 
America or elsewhere and feared that it was unwise for the Institu- 
tion to continue to conduct the operations there. On all of these 
accounts it seemed necessary for Dr. Abbot to go to South America 
and deal with these several matters. 
In accordance with the sundry civil act, which failed of passage on 
March 4, 1919, but was approved July 19, 1919, the following authori- 
zation was secured : 
The unexpended balance of the appropriation " For observation of the total 
eclipse of the sun of June 8, 1918, and so forth," is reappropriated and made 
available for observation of the total eclipse of the sun of May 28, 1919, visible 
in Bolivia. 
The two 11-foot focus 3-inch cameras employed by the Smithsonian 
observers at Wadesboro, N. C, in 1900, and again by Mr. Aldrich in 
1918, were equipped with a collapsible tube and other mechanism, 
so that they could be speedily arranged with equatorial clock-driven 
motion to photograph an eclipse in South America. Mr. Moore, at 
Calama, was instructed to arrange to join Dr. Abbot with the pyranom- 
eter employed there, so as to observe the degree of darkening of the 
sky and sun as the eclipse progressed. Arrived at Calama, the appa- 
ratus was repacked for use in the field, and Messrs. Moore and Abbot 
proceeded to La Paz, Bolivia, where, owing to the kindness shown 
by Mr, Babbage, of the railroad, arrangements were made to observe 
close to the railroad station at El Alto, situated about 1,500 feet above 
La Paz, at an altitude of about 14,000 feet above sea level. The day 
of the eclipse. May 29, proved very favorable. The sky was entirely 
cloudless in the neighborhood of the sun for several hours. Mr. 
Moore had observed during the day before and during the night, and 
continued his observations each minute throughout the totality and 
the succeeding partial phase up until about two hours after sunrise. 
Dr. Abbot had set up and adjusted the photographic telescope with 
Mr. Moore's aid, and except for one defect it operated perfectly. 
This was that since the eclipse took place so very early in the morn- 
ing, only 20 minutes after sunrise, the rate of motion of the sun 
above the horizon was not uniform with that which would occur in 
the middle of the day, owing to refraction. The apparatus had only 
been set up the day before, so that there was not time to work out 
this matter to know exactly how to rate the clock at the moment of 
eclipse. Preliminary observations of May 28 had indicated that the 
clockwork ran a little too slow. During the day it was speeded up 
