286 CARNEGIE INSTITUTION OF WASHINGTON. 



LAND-SURVEY WORK AND SPECIAL EXPEDITIONS. 



The war and the resulting world conditions have restricted land field 

 work to a great extent during the year. It has been possible, however, 

 to secure valuable data at new stations as well as secular-variation 

 stations, particularly in Africa and South America. 



An important problem concerning the land field work is that of 

 securing absolute time for the determination of longitudes. Inquiry 

 and study regarding wireless methods for the reception of time signals 

 was undertaken. Mr. Brown particularly made inquiries regarding 

 small portable types of receiving apparatus with a telephone relay 

 instead of an amplifier system. It is hoped that a portable receiving 

 outfit may be developed which will be compact and light enough to 

 form part of the regular equipment of our field parties. 



AFRICA. 



In Africa, Messrs. Bauer and Johnston made magnetic observations 

 at three stations in Liberia, one of these, namely, Russworm Island, 

 being a close reoccupation of the station occupied by Observer Sawyer 

 in 1914. These observations were made on the trip to carry out the 

 special program of magnetic and atmospheric-electric observations 

 during the solar eclipse of May 29 at Cape Palmas. (See p. 311.) 



Observer F. Brown, who reentered the service of the Department 

 on March 1 after his discharge from the British Army, made mag- 

 netic observations during April, while en route to the field, at Sec- 

 condee and at Accra on the Gold Coast. He arrived at Douala, Cam- 

 eroun, on May 2, and made that point his headquarters for the work 

 in Cameroun. After securing repeat observations at the C. I. W. 1915 

 station and at a secondary station at Douala, he worked along the 

 Northern and Midland railways, occupying new stations at Nkong- 

 Samba, Lum, Kompina, and Edea. During May 24 to June 2 he made 

 special eclipse observations at Campo, Cameroun, on the coast midway 

 between Douala and Libreville. He also occupied on June 3 a station 

 at Rio Campo in Spanish Guinea. He left Kribi, Cameroun, June 11, 

 for Fort Lamy near Lake Tchad, traveling via Ebolowa, Yaounde, Yoko, 

 Tibati, Ngaumdere, Garua, and Dikoa; he arrived at Yoko on July 11 

 and expected to arrive at Dikoa early in August and to proceed thence 

 to Nola and Wesso via Lai, Gore, Carnot, and the Kongo Paver. From 

 Wesso he plans to return to Douala overland, via Molundu and Abong- 

 Mbang, to railhead of the Midland Railway at Esseka, arriving at 

 Douala probably early in December 1919. 



ASIA. 



At the end of the last report-year, Observer H. E. Sawyer was en 

 route to the office after an extended survey trip in Africa from Lake 

 Tchad overland to Khartoum and thence to repeat C. I. W. stations 



