August 12, 



18S7.] 



SCIENCE. 



81 



social pleasures the gathering brings, this may fulfil its large open- 

 ing promise of being a fruitful and happy season to us and to our 

 association. 



— Dr. E. Naumann, late director of the geological survey of 

 Japan, has published an essay on the influence of the structure of 

 the earth upon the phenomena of terrestrial magnetism. His re- 

 searches in Japan show that the magnetical lines are to some ex- 

 tent influenced by the/ossa magna, a great fault which crosses the 

 islands in a direction south-east by north-west. By studying the 

 direction of the magnetical lines in connection with the geological 

 structure of other countries, the author comes to the conclusion, 

 that, in the vicinity of faults and folds, the magnetical lines 

 show remarkable irregularities, and that a connection exists between 

 both phenomena. Recent researches by Ciro Chiistoni on the in- 

 tensity of terrestrial magnetism in Italy (Atti dclla R. Accadeinia 

 dei Lhicet, 1887, p. 200) show irregularities of the magnetical 

 elements in the eastern part of V'enetia, on the western part of the 

 coast of Liguria, and iii Val Pelice. These places coincide 

 with centres of seismical disturbances, and suggest a connection 

 between geological and magnetical phenomena. It seems, how- 

 ever, that the available material is still too incomplete for a thor- 

 ough study of the question at issue, the magnetical surveys not 

 being of a sufficiently detailed character. 



— Charles E. Putnam of Davenport. Ic, died July 19. 



— Those interested in Spiritualism will read with special interest 

 Prof. Carvill Lewis's account of two sittings with the noted English 

 medium, Englinton. This medium is such a tower of faith to 

 believers, and has deceived so many, that so glaring an exposure 

 of his methods as Professor Lewis gives is especially valuable. The 

 article is published in the Proceedings of the English Society for 

 Psychical Research, May, 1887. 



— The readers of Science know from our notes on the explora- 

 tion of Africa how rapidly one discovery follows another, and that 

 it is difficult to keep a map up to date. This fact has induced J. 

 Perthes to publish a second edition of his large map of Africa in ten 

 sheets (i : 4,000,000). The student of the geography of Africa will 

 find this map, which contains an enormous amount of detail, and 

 which is in every respect up to the date of publication, a valuable 

 help in his researches. The routes of explorers, the tribes with 

 whom they came into contact, and the character of the land they 

 traversed, are shown in the map ; deserts, steppes, and regions 

 with tropical vegetation, including savannas and woods, beiitg dis- 

 tinguished by different colors. An important feature of the map, 

 and one necessary for the critical study of geography, is the dis- 

 tinction between countries which are really explored and those 

 which are known by report only ; the former being written with 

 heavy letters, the latter with light ones. The new edition, of which 

 two sheets — Kongo and Abyssinia — have been published, con- 

 tains so much new material, that the section ' Kongo ' is practically 

 a new map. The results of the journeys of Kapello and Ivens, Reich- 

 ard, von Francois, Kund and Tappenbeck, Wolf, Buttner, Grenfell, 

 Junker, and the observations of Captain Rouvier, have been used 

 in constructing this sheet. The important results of these journeys 

 were published in our map of Central Africa some time ago. The 

 observations of Chavanne and other visitors of the Lower Kongo 

 induced the author, H. Habenicht, to include that region in the 

 zone of steppes .occupj^ing south-west Africa. In Section 6, 



' Abyssinia,' the routes of Cecchi and Chiarini have been inade use 

 of, and — what will be welcome to most readers — Emin Pacha's 

 province, his stations, and those of the Kongo Free State, have 

 been marked by separate colors. The political boundaries have 

 been corrected according to recent treaties and annexations. 



LETTERS TO THE EDITOR. 



*»* The attention ofscieiitific men is ealled to the advantages of the correspondence 

 columns ofScisttCE /or placing promptly on record brief preliminary notices of 

 their investigations. Twenty copies of the number containing liis co/nmunicaiion 

 will be furnished free to any correspondent on request. 



The editor will be glad to publish any queries consonant "with the character of 

 the journal. 



Correspondents are requested to be as brief as possible. The ivriiers name is 

 in all cases required as proof of good faith. 



The Sonora Earthquake. 



The past month has been spent by me in Sonora, U.S. Mexico, 

 in examining the scene of the greatest disturbances during the re- 



cent earthquake of May 3. This trip has required mountain-travel 

 of about seven hundred miles, horseback and on foot; fully one- 

 half, the latter. While it is impossible now to give the complete 

 results of my explorations, a brief summary may prove interesting. 



There is not now, nor has there been, lava eruption or crater 

 volcano. I visited every locality in the Sierra Madres where such, 

 phenomena had been reported — fruitlessly. There is a grand 

 fault extending along the eastern side of the San Bernardino and 

 Yaqui River valleys for nearly one hundred miles. This fault has 

 a general northerly and southerly strike, with a dip of from 45° to 

 vertical ; and the difference in level of the two sides is for fifty 

 miles an average of eight feet. It lies close to the foot of the 

 mountain-ranges, where the mesa drift joins the steeper part of the 

 chain, until it crosses the Yaqui, where it goes directly into the 

 mountains. There are numerous minor faults and fissures ; and 



•ovOiEvaofFauU 



^^T ws/araifoUowed 



HEIGHT IN FEET. 



Fronteras, 3,350. 

 Batepito, 2,790. 



Bacerac, 3i^50. 



the entire valley of the San Bernardino is apparently sunk from 

 two to four feet. The relative level is changed that much. This 

 condition exists also on the Babispe River above and for soine dis- 

 tance below Babispe, and on the Yaqui at and below its junction 

 with the San Bernardino. Almost every water-course in the dis- 

 turbed area has changed in the same way. 



The town of Babispe was totally destroyed, forty-two lives lost 

 out of a population of seven hundred. No other town in Sonora 

 suffered much. Extensive evidence exists of irruption of water, 

 sand, and fiery gases. As stated in my first letter, mountain-fires 

 succeeded the first shock. These were caused by the ignited gases 

 and falling bowlders. Time data in Mexico, away from the rail- 

 ways, are unprocurable, none existing. The general fact that the 

 first shock took place May 3, about 3 p.m., and that it came from a 

 westerly direction, is all that can be obtained. 



It is much to be lamented that the ground was not thoroughly 

 explored before the beginning of the rainy season, which set in oa 

 the 14th of June with a violence unknown since 1881. This will 



