278 CARNEGIE INSTITUTION OF WASHINGTON. 



unlikely that the atmospheric-electric fluctuations will prove of special 

 interest, not only to students of atmospheric electricity, but also to those 

 investigating the causes of the disturbing or "stray" effects frequently en- 

 countered in wireless transmission. Pending the completion of the experi- 

 mental work at the Watheroo Observatory and at the laboratory in Wash- 

 ington, it has been considered best to defer, probably until 1924, installations 

 for earth-current observations at the Huancayo Observatory. Considerable 

 assistance has again been received from the Peruvian Government and from 

 the American embassy. (The Director hopes in the near future to make an 

 inspection trip to the Observatory.) 



Apia Observatory, Samoa. — The cooperation with the New Zealand Govern- 

 ment at the Apia Observatory, referred to in the last Annual Report (p. 312), 

 was maintained during the year in order to continue the atmospheric-electric 

 and related meteorological observations, pending other arrangements. As 

 heretofore, the New Zealand Government has kindly furnished quarters to 

 observers of the Department, and has extended many other courtesies through 

 its officials at Apia. A new atmospheric-electric observatory was constructed 

 during March on the site of the old building and a small building was provided 

 for a laboratory. The house used as a residence by the Department's repre- 

 sentative was repaired without charge by the Public Works Department. 

 Continuous records of the potential gradient for 85 per cent of the time were 

 obtained, beginning April 1, with a Benndorf recording electrometer. Occa- 

 sional conductivity observations were secured, and meteorological observa- 

 tions were taken twice a day. It is expected that during the latter part of 

 the year potential-gradient records may be obtained with a second Benndorf 

 recording electrometer at various positions around the grounds of the observa- 

 tory simultaneously with the observations in the atmospheric-electric observa- 

 tory. From November 1921 to March 1922, Dr. H. M. W. Edmonds was the 

 Department's representative at the Observatory and thereafter Mr. Andrew 

 Thomson, who had acquired special experience in atmospheric-electric work 

 aboard the Carnegie, during her two years' cruise, 1919-1921. (See reference 

 p. 281, regarding the Director's attendance at a special meeting of the Samoa 

 Observatory Honorary Board of Advice, held at Wellington, July 4 and 5. 

 Owing to uncertainty of steamer connection, it was necessary, to his regret, 

 to abandon an intended visit to the Apia Observatory. The Director called 

 on his excellency, the Governor of New Zealand, Lord Jellicoe, who showed 

 no little interest in the continued welfare of the Apia Observatory.) 



MacMillan Baffin Land Expedition. — As a result of the Department's 

 cooperation with the MacMillan Baffin Land Expedition, successful observa- 

 tory work was accomplished for 73^ months, beginning with November 1, 

 1921, at the winter quarters of the expedition in southwestern Baffin Land 

 at Bowdoin Harbor. Continuous photographic records of magnetic declina- 

 tion, horizontal intensity, and vertical intensity, and of the electric potential- 

 gradient of the atmosphere, were obtained, as also the necessary control 

 magnetic observations and scale-value determinations. The type of tempo- 

 rary observatory designed by the Department proved satisfactory. Meteor- 

 ological and tidal observations were likewise obtained, and 69 specimens of 

 rock were collected in Baffin Land and Labrador for examination by the 

 Geophysical Laboratory. 



Washington, District of Columbia. — Redeterminations as necessary of in- 

 strumental constants and comparisons and standardizations of magnetic in- 

 struments before and after assignment for field use were continued in the 

 standardizing magnetic observatory. A compass-variometer for special in- 

 vestigations of local magnetic anomalies and several dip-circles were calibrated 

 for different values of intensity and inclination, varying the magnetic field as 



