608 



SCIENCE 



[N. S. Vol. XLIX. No. 1278 



Davidson for photograpliing the field of stars 

 round the sun on the occasion of the total 

 eclipse of the sun last week (May 29), the sky 

 wais clear for at least part of totality, and that 

 the program was satisfactorily carried out. 

 The photographs have been developed, and all 

 the stars expected are shown on the plates 

 taken with the astrographic lens, as well as 

 on those taken with a second telescope lent by 

 Father Cortie. The expedition will remain at 

 Sobral until the necessary comparison photo- 

 graphs are taken in situ. The message from 

 Professor Eddington at Prince's Island, off the 

 coast of West Africa, which reads " Through 

 cloud, hopeful," may be taken to imply that 

 some success will also be derived from the 

 work of this expedition. 



It wiU be remembered that Professor Ed- 

 dington and Mr. Cottingham were provided 

 with the 13-inch object-glass of the astro- 

 graphic telescope of the Oxford University Ob- 

 servatory, whilst the observers in Brazil had 

 the similar object-glass from Greenwich, and 

 that the program of both stations was to take 

 photographs of the stars that surrounded the 

 sun, of which there are at least twelve within 

 100' of the sun's center of photographic mag- 

 nitude ranging from 4.5 to 7.0, for the pur- 

 pose of testing Einstein's relativity theory of 

 gravitation, and also the hypothesis that 

 gravitation, in the generally accepted sense, 

 acts on light. Photographs that have been 

 taken during the eclipse will be compared with 

 others that have been, or will be, taken of the 

 same stars in the night sky to detect any dis- 

 placement that may be considered to be due to 

 the presence of the sun in the field. 



There is at present no information as to the 

 type of the corona, and apparently few observ- 

 ing parties have been organized to make ob- 

 servations to record this. From a note in the 

 daily press last week, said to emanate from the 

 Yerkes Observatory, it seems not unlikely that 

 a large prominence may have been on the 

 limb of the sun at the time of the eclipse. 



It had been announced that the Cordoba Ob- 

 servatory would dispatch an expedition to 

 Brazil, and that ix)ssibly Professor Abbot, of 

 the Smithsonian Institution, would proceed to 



La Paz, Bolivia, where the eclipse happened at 

 sunrise, with coronal cameras and with instru- 

 ments for measuring the sky radiations by day 

 and night, but it is too early to have heard of 

 any results of such observations. Also it has 

 been announced that Professor D. P. Todd 

 would take photographs of the eclipse from an 

 aeroplane at a height of 10,000 feet from the 

 neighborhood of Monte Video, where the 

 eclipse would only be partial. 



REVISTA MATEMATICA HISPANO-AMERICANA 



Under the above title a new mathematical 

 periodical began to appear at the beginning 

 of the present year, which may be of some 

 general scientific interest both on account of 

 territory covered by its title and also on ac- 

 count of some of its unique aims. One of 

 these is the publication of corrections of errors 

 found anywhere in the mathematical litera- 

 ture. These corrections are to appear in a 

 special section headed Glosario Matematico. 



While mathematics is an exact science its 

 literature is by no means free from differ- 

 ent types of errors, varying from slight 

 oversights to those relating to matters of 

 fundamental importance. The majority of 

 these errors are readily recognized by the 

 careful reader and need only to be pointed out 

 tfj be acknowledged; but, as mathematics 

 grades gradually into various inexact sciences 

 — such as philosophy, history and physics — it 

 is clear that a part of its literature relates to 

 the eternal approximations towards an un- 

 stable limit and here the question of errors 

 connects up with endless words. 



The corrections in the Bevista, published at 

 Santa Teresa, 8, Madrid, Spain, are supposed 

 to be confined to the former type of errors and 

 these corrections may serve the double purpose 

 of curtailing the repetition of such errors and 

 of pointing out somewhat slippery ground in 

 mathematical fields. It is also of interest to 

 walk securely over ground where experts 

 slipped by overlooking lurking dangers which 

 their slipping caused to change to well- 

 marked pitfalls. 



General interest in this new mathematical 

 I)eriodical may perhaps be enlisted by the can- 



