WEATHER BUREAU. 87 



nally of the ^Massachusetts Institute of Technolo<^y and now in 

 chai-fje of the work under the Weather Bureau. On special occasions 

 the observations are extended to include the volcano at Mauna Loa. 

 A visit to some part of Mauna Loa more than once a year is 

 desirable. P^xperience proves that Mauna Loa erupts more fre- 

 quently from places along- its rift sj'stems outside of the summit 

 crater than at the summit crater itself. There has been no activity 

 at the summit crater durin^^ the 1919 outbreaks from the south flank, 

 and in 1920 Mauna Loa is quiet. 



Seismometric re«^istration has continued as heretofore, with no 

 unusual events durin^^ the period. The Hilo instrument has been 

 operated nearly continuously. 



The general results of observations at Kilauea are brought together 

 from month to month in a small bulletin, wliich is issued regularly. 

 In addition, a summary has been issued to newspapers and printed 

 with fair regularity. 



INSTRUMENTATION. 



The instrumental equipment of the field stations has been main- 

 tained in a serviceable condition, l^ut at a number of stations re- 

 pairs to roof equipment needed could not be made owing to difficulty 

 in getting satisfactory estimates. 



STORM-WARNING EQUIPMENT. 



The three-lantern system was completed during the fall, and is 

 now in effect throughout the country. The storm-warning equip- 

 ment destroyed in the Corpus Christi district by a hurricane is now 

 being replaced, the larger portion of the expense coming out of 

 funds for 1920. Few additions or improvements have been possible 

 with the limited funds at our disposal. 



NEPHOSCOPES. 



The Bureau now has at the factory ready for distribution 100 

 nephoscopes of a new pattern. 



EVAPORATION. 



The evaporation stations have not been increased in number, on 

 account of expense and because it was throught best not to add to 

 the duties of stations at this time. 



INVESTIGATIONS IN SOLAR RADIATION. 



Observational work has been maintained at Washington, D. C, 

 Madison, Wis., Lincoln, Xebr., and Santa Fe, N. Mex., as in previous 

 years. 



A summary has been prepared of the measurements made previous 

 to July. 1919. and utilized in the determination of nverage monthly 

 sunshine intensities in the United vStates east of the Rock Mountains. 

 These have been published in the Monthly Weather Eeview for No- 

 veml)er. 1919, in the form of charts, which are the oi\\y sunshine in- 

 tensity charts yet published for anj' country. 



