REPORT OF THE SECRETARY 109 
$55,000 to be expended by Dr. C. G. Abbot for the following 
purposes : 
1. To select the best location in the Eastern Hemisphere for a 
solar-radiation station to cooperate with the two now operated by 
the Astrophysical Observatory for the measurement of solar 
variation. 
2. To equip the station selected. 
3. To send an expedition to be known as the National Geographic 
Society Solar-Radiation Expedition Cooperating with the Smith- 
sonian Institution to continue solar-radiation observations as long 
as the grant permits, estimated at four years. 
In furtherance of this project, Mr. W. H. Hoover, hitherto direc- 
tor of the Argentine solar-radiation observatory at La Quiaca, and 
Mr. F. A. Greeley, hitherto assistant at Harqua Hala and at Monte- 
zuma, were engaged as director and assistant for the new station. 
Apparatus was ordered, and Mr. Andrew Kramer, instrument maker 
to the Astrophysical Observatory, was transferred to construction 
work under the National Geographic Society’s grant. Mr. Aldrich 
undertook the finer work of constructing galvanometer, pyrheliom- 
eter, bolometer, and pyranometer parts, and of standardizing them 
as well as oversight over the preparations. 
Doctor Abbot went abroad to Algeria, Egypt, Baluchistan, and 
South West Africa to select the location. Preference was given to 
the Brukkaros Mountain in South West Africa (Jong. 17°-48’ E., lat. 
25° 52’ S.). This is an isolated cup-shaped peak 5,002 feet in ele- 
vation, rising precipitously from a level plateau of 3,000 feet eleva- 
tion. The average yearly rainfall in the vicinity is 314 inches. A 
Hottentot reservation surrounds the mountain, and the nearest town 
is Berseba, 7 miles south, where there are only two white inhabitants, 
the others Hottentot. Supplies would come from Keetmanshoop, 60 
miles distant by auto. Water in small but sufficient quantity is 
found on Mount Brukkaros. 
The construction is undertaken by the public-works department of 
South West Africa under Mr. A. Dryden, inspector. It is proposed 
to have a tunnel for instruments, a small dwelling for observers, a 
shop, a reservoir, and garage. Wire telephones will be installed by 
the Government of South West Africa and rented to the expedition. 
Work was begun in April and it was hoped to send the expedition 
in early autumn. 
Though so isolated, the location is in other respects very promising. 
The average rainfall of only 314 inches occurs as a rule one-third in 
February, one-third in March, and the rest scattering. Doctor 
Abbot was in the vicinity 12 days in March, of which 11 would have 
been favorable for observing. If this is characteristic of the rainy 
season, it promises well for the year as a whole. It is also favorable 
