DEPARTMENT OF TERRESTRIAL MAGNETISM. 289 



Iguatu, Fortaleza, Camocim, Sobral, Nova-Russas, Amarragao, Papa- 

 gello, Natal, Pernambuco, and Para, all in Brazil, and at Barbados. 

 Valuable secular-variation data result from the reoccupations at For- 

 taleza, Pernambuco, Para, and Barbados. Messrs. Wise and Thomson 

 sailed from New York City for Brazil on March 26, and returned to 

 the office August 6. 



SPECIAL EXPEDITIONS, 



Special observations in accordance with the Department's program 

 for the total solar eclipse of May 29, 1919, were made at the following 

 stations: Cape Palmas, Liberia; Campo, Cameroun; Sobral, Brazil; 

 Huayao, Peru; Puerto Deseado, Territory of Santa Cruz; the observa- 

 tory near Watheroo, Western Australia; and Washington. Detailed 

 instructions were prepared for making absolute observations of diurnal 

 variation with magnetometers and earth inductors in declination, 

 horizontal intensity, and inclination for some stations where vario- 

 meters were not available. 



Africa. — The work at Cape Palmas, Liberia, was carried out by 

 Director L. A. Bauer and Magnetician H. F. Johnston. After the 

 necessary preparations and purchases of stores and supplemental 

 equipment, the party left England on April 12, arriving at Cape Palmas 

 May 5. The magnetic observations included diurnal variation with 

 absolute instruments in declination, horizontal intensity, and inclina- 

 tion, in full accord with program, on the day of the eclipse and preced- 

 ing and following it, together with necessary control observations. 

 Complete meteorological observations were made during May 20 to 

 June 5, using an equipment loaned by the British Meteorological 

 Office, through the courtesy of Director Shaw. Special equipment had 

 also been taken from England for the purpose of making atmospheric- 

 electric observations of potential gradient. The unfortunate deteriora- 

 tion and consequent failure of the stock of dry cells, however, pre- 

 vented the use of the apparatus (no dry cells could be procured at Cape 

 Palmas). Observations of shadow-bands were also undertaken. The 

 meteorological conditions on May 29 were favorable. The party left 

 Cape Palmas for Liverpool on June 8, arriving there June 25. Con- 

 siderable interest was shown, as well as assistance rendered, by Hon. 

 G. T. Brewer, superintendent of Maryland County of Liberia, and by 

 the officials and citizens of Cape Palmas. For further account, see 

 abstract, page 311. 



Successful observations in accordance with the special program, 

 including diurnal variations in declination for the period specified on 

 May 28, 29, and 30, and absolute observations for the three elements 

 on May 26 and 31, were obtained by Mr. Brown at Campo, Cameroun. 

 The work was done in a non-magnetic observing-hut 12 feet square, 

 built of bush timber and palm matting, all fastened with bush rope. 

 Complete 24-hour diurnal-variation series of declination were made 



