DECEMBER 27, 1918] 
while for the advancement of knowledge. The 
actual workers therein should be full-time 
men. Whether the titular chief should always 
be such is an undecided question and is largely 
dependent upon the personal equation. 
Such laboratories as these are the glory of 
the Harvard Medical School. To the young 
men who are to be the leaders of the future 
belongs the present opportunity. The lands 
of Europe are wasted and impoverished by 
war. Only the wounded and the physically 
unfit were allowed to study medicine in Eng- 
land last winter. The men of England and 
the men of France have fought for four long 
years; ours for four months. The young 
physicians of America of the present. genera- 
tion have the obligation and may, perhaps, 
deserve the credit of establishing ip the days 
to come, the dreams for medicine of Magendie 
and of Claude Bernard, thus insuring a 
notable scientific era in this great land of 
ours. Only thus can medicine progress; only 
through observation and experiment can the 
world grow in wealth of knowledge. We may 
thus endeavor, “as Lord Bacon says, to frame 
the human understanding anew.” 
Granam Lusk 
THE SMITHSONIAN “SOLAR CON- 
STANT” EXPEDITION TO 
CALAMA, CHILE 
In 1916 Secretary Walcott appropriated from 
the income of the Hodgkins Fund to equip and 
maintain for several years such a station in 
South America, but owing to the war it was 
temporarily located in the North Carolina 
mountains in 1917. The station proved very 
cloudy, and now it has proved possible though 
very expensive to go to Chile. 
Dr. C. G. Abbott has reported to the Na- 
tional Academy of Sciences that after corre- 
spondence with the South African, Indian, 
Argentine and Chilean meteorological services 
he became convinced that near the nitrate 
desert of Chile is to be found the most cloud- 
less region of the earth easily available. Dr. 
Walter Knoche, of Santiago, has most kindly 
furnished two years (1913 and 1914) of un- 
SCIENCE 
635 
published daily meteorological records for a 
number of Chilean stations. In his judgment 
the best station is Calama on the Loa River, 
Lat. S. 22° 28’, Long W. 68° 56’, altitude 2250 
meters. For the two years the average num- 
ber of wholly cloudless days is at 7 a.M., 228; 
2 p.M., 206; 9 p.wt., 299; and of wholly cloudy 
days, none. The precipitation is zero; wind 
seldom exceeds 3 on a scale of 12; temperature 
seldom falls below 0° or above 25° O. 
The expedition, Director Alfred F. Moore, 
Assistant Leonard H. Abbot, reached Calama 
June 25, 1918, equipped with a full spectro- 
bolometric, pyrheliometric and meteorological 
outfit of apparatus, as well as with books, tools, 
household supplies and everything foresight 
could furnish to make the work successful and 
life bearable. The Chilean government has 
facilitated the expedition in many ways, and 
the Chile Exploration Company has given the 
expedition quarters and observing station at 
an abandoned mine near Calama. Many others 
in Antofagasta, Chuquicamata and Calama 
have been of great assistance. 
The apparatus is set up in an adobe build- 
ing about 30 feet square, in which the ob- 
servers have sleeping apartments. A 15-inch 
two-mirror coelostat reflects the solar beam to 
the slit of the spectro-bolometer. A Jena 
ultra-violet crown glass prism and speculum 
metal mirrors are used in the spectroscope 
The linear bolometer is in vacuum, and con- 
structed in accord with complete theory for 
greatest efficiency. Its indications as meas- 
ured by a highly sensitive galvanometer are 
recorded photographically on a moving plate 
which travels proportionally to the movement 
of the spectrum over the bolometer. Suc- 
cessive bolometric energy spectrum curves 
each occupying 8 minutes of time are taken 
from early morning till the sun is high and 
are thus recorded on the plate. Their inten- 
sity indications at 40 spectrum positions are 
reduced by aid of a special slide rule plotting 
machine. 
A pair of silver disk pyrheliometers is read 
simultaneously with each spectro-bolographic 
determination. Measurements of humidity, 
temperature, and barometric pressure accom- 
