November 25, 1921] 



SCIENCE 



513 



Dr. Rusby states that the journey from 

 Espia, at the head of navigation on the Bopi 

 River, down to Huachi, was accomplished suc- 

 cessfully except for the loss of five boxes of 

 provisions and ammunition. The loss of their 

 ammunition leaves the party in a rather pre- 

 carious condition as they were depending on it 

 for obtaining not only museum specimens of 

 rare birds and small mammals but also to sup- 

 ply the camp with fresh meat. 



Among botanical collections are included 

 specimens of the " tree of life." This name 

 'is a literal translation of the Spanish name 

 "Arbol de la Vida," given to the " Boldo " 

 plant, so called because of its use by the natives 

 for medicinal purposes. Photographs were 

 made of what Dr. Rusby considers the largest 

 true cactus in the world, which rises to the 

 height of a good-sized tree and with a limb 

 spread of forty feet or more. 



Many forms of insect life have been col- 

 lected. With these, as in the case of plant life, 

 specimens collected in one of these deep Andean 

 valleys may differ entirely from those of a sim- 

 ilar valley very closely adjacent. 



The party expected to arrive at Rurren- 

 abaque, Bolivia, about October 1 and by this 

 time are probably forcing their way into the 

 depths of the Bolivian jungle in the vicinity of 

 Lake Rocagua. 



THE ECLIPSE EXPEDITIONS TO CHRISTMAS 

 ISLAND 



According to an article in the London 

 Times, with the aid of the Joint Permanent 

 Eclipse Committee of the Royal Society and 

 the Royal Astronomical Society, the Royal 

 Observatory at Greenwich is sending an expe- 

 dition to Christmas Island to observe the 

 total eclipse of the sun which will occur on 

 September 21 next year. 



The Greenwich party will consist of Mr. H. 

 Spenser Jones, Chief assistant, and Mr. P. 

 J. Melotte, the discoverer of the eighth satel- 

 lite of Jupiter. They will leave England 

 early in February for Singajwre, whence they 

 and their equipment will be conveyed to the 

 island by a steamer belonging to the Christ- 

 mas Island Phosphate Company, which is 

 giving valuable help to the project. 



A joint Dutch and German expedition, the 

 personnel of which will include Professor 

 Voute of Batavia University and Professor 

 Freundlich of Germany, will also go to Christ- 

 mas Island, and it is possible that Professor 

 Einstein will himself be present to observe 

 the eclipse. 



It is hoped to confirm the results obtained 

 by the British expeditions at Principe and 

 Sobral during the eclipse of May, 1919, when 

 Einstein's prediction as to the value of the 

 deflection of a ray of light passing through a 

 gravitational field was verified by measure- 

 ments of the position of start in the immedi- 

 ate neighborhood of the sun during totality. 



It has been arranged that the Greenwich 

 expedition, which will have erected its instru- 

 ments by May, shall carry out an extensive 

 program of photometric work. Based on the 

 Harvard standard sequence of stars at the 

 North Pole comparisons will be made of areas 

 in South Declinations 30 deg. and 45 deg., 

 with areas in North Declination 15 deg. 

 Magnitudes of stars in the latter zone have 

 already been determined at Greenwich in di- 

 rect comparison with those in the North 

 Polar area, and the photographs to be taken 

 at Christmas Island will enable work on these 

 lines in the northern and southern hemis- 

 pheres to be linked up and carried on to the 

 South Polar area by southern observatories. 

 The equipment to be taken by the British 

 party will include the 13 in. astrographic tele- 

 scope used in the making of the Greenwich 

 sections of the international photographic 

 chart of the sky. 



The path of totality will begin in Abys- 

 sinia, pass over the center of Italian Somali- 

 land and across the Maldive Islands, where 

 Mr. J. Evershed, the director of the Kodai- 

 kanal Observatory (India), will be stationed. 

 At the Maldives the duration of totality will 

 be 4 min. 10 sec. with the sun 34 deg. above 

 the horizon. At Christmas Island the dura- 

 tion will be only 3 min. 42 sec., but the sun 

 will be Y8 deg. above the horizon. The maxi- 

 mum duration, nearly 6 min., occurs over the 

 Indian Ocean where no observing station 

 exists. After leaving Christmas Island the 



