258 CARNEGIE INSTITUTION OF WASHINGTON. 



L. Hosmer, at Woburn, near Boston, Massachusetts, by C. T. Knipp 

 at Urbana, Illinois, by H. B. Wahlin at Columbia, Missouri, by J. 

 M. Kuehne, at Austin, Texas, and by W. J. Raymond at Berkeley, 

 California; these observers acted under the direction of the Depart- 

 ment and cooperated with it. At Lakin a set of magnetograph instru- 

 ments was put into operation, in charge of Observer D. M. Wise, 

 assisted by A. Thomson and M. B. Smith. Some special observations 

 were also made in the neighborhood of Pikes Peak for the purpose of 

 studying the possible effect of altitude on the values and variations 

 in the magnetic elements due to change of altitude. 



SOUTH AMERICA. 



After crossing the Andes from the Pacific coast by way of La Paz 

 and the Beni River, Observer Allen Sterling arrived at Manaos, Brazil, 

 on October 29, 1917. The plan had been to ascend as many of the 

 tributaries of the Amazon as suitable opportunity should afford, but 

 difficulties arising (chiefly from economic conditions) limited the num- 

 ber of these to two, the Purus and the Tapajoz. After considering the 

 different plans for ascending the Purus River, Mr. Sterling decided to 

 rely on the unscheduled but rather frequent river steamers for trans- 

 portation from point to point. In this way he succeeded in establishing 

 8 stations between Manaos and Xapury on the Acre River, an affluent 

 of the upper Purus, having left Manaos on November 20 and arriving 

 at Xapury on January 8, 1918. Returning over the same route to 

 Manaos, he proceeded eastward to Santarem, and from there to Obidos, 

 where he observed at the C. I. W. station of 1911, on February 10. 



Returning to Santarem, also a repeat station, Mr. Sterling arranged 

 a short trip up the Tapajoz River, which he succeeded in ascending 

 as far as its confluence with the Sao Manoel River. The first portion 

 of this journey was made by river steamer, after which it was neces- 

 sary to make use of cargo boats propelled by motor in part, and handled 

 in difficult places by a crew of oarsmen, assisted by the passengers as 

 required. He succeeded in making observations at three points, a 

 greater number being made impracticable by the serious illness of a 

 member of the crew which prevented making the necessary stops. As 

 no further side expeditions seemed to be feasible, Mr. Sterling went 

 directly to Para after his return to Santarem, making one stop at 

 Almeirem, a C. I. W. station of 1911. From Para 4 stations were 

 occupied in the immediate vicinity, including the repeat station of 

 Pinheiro. 



Leaving Para on May 13, Mr. Sterhng observed at Cayenne, Para- 

 maribo, Georgetown, and New Amsterdam, in the Guianas, finally 

 leaving Georgetown for New York, where he arrived on July 8, 1918. 

 Since arriving at Manaos in October, Mr. Sterling occupied 26 sta- 

 tions, 8 of which were exact or close reoccupations of stations pre- 



