REPORT OF THE SECRETARY 109 



one or two days occasionally occur. But the data were resolved into 

 15 series, averaging about 1 year in length each, when in each series 

 from 2.5 to 8.5 times as much precipitation fell on the day of 

 maximum as on the day of minimum expected precipitation. 



NEW FIELD STATIONS 



After a reconnaissance throughout southwestern New Mexico, 

 A. F. Moore located a new solar-observing station on Burro Mountain, 

 near Tyrone, N. Mex., approximately long. 108°33', lat. 32°40', alt. 

 8,000 ft. This station was made readily accessible to motor cars 

 through the valued cooperation of the United States Forest Service. 

 Water was developed about 2 miles down the road, and tanks are 

 kept filled at the summit for gravity circulation. Telephone com- 

 munication has also been established. 



The observatory structures, comprising a tunnel and piers for in- 

 struments, bungalows for the observers' families, garages, and water 

 tanks were built to specifications of Mr. Moore by Jack Heather, of 

 Lordsburg. 



The observing instruments formerly at Mount St. Katherine, and 

 before that at Mount Brukkaros, were installed at the new Tyrone 

 Station. Observations of the solar constant were begun there in 

 January 1939. 



As in old Mexico, the precipitation in southwestern New Mexico 

 is almost altogether in the months July to September in normal 

 years, and at Lordsburg averages only about 9 inches per year. We, 

 therefore, hoped this new station would serve in a valuable supple- 

 mentary way with our stations in California and Chile, where the 

 months December to February are the worst, for continuous daily 

 records. The past winter proved exceptional, as there was a snow- 

 fall on Burro Mountain of 72 inches. No such great fall of snow, 

 we are informed, has occurred there for 20 years before. 



OTHER FIELD STATIONS 



Solar-constant observing has been continued at Table Mountain, 

 Calif,, and Montezuma, Chile, as in previous years, on every favorable 

 day. Usually about 75 to 80 percent of the days of the year are cloud- 

 less enough for observations to be made at these stations. Exception- 

 ally deep snow fell on Table Mountain in this past winter, amounting 

 to over 11 feet in all. 



At John A. Roebling's suggestion, all three observing stations have 

 been equipped with excellent concrete tennis courts, constructed with 

 grants of funds by Mr, Roebling. 



