Maech 11, 1887.] 



SCIENCE. 



229 



south side of the Anti- Atlas, and drains its south- 

 ern slope. It was crossed by Leopold Panet in 

 1850, about fifty miles above its mouth ; by Si Bu- 

 Moghdad in 1861, about twenty-five miles lower. 

 Eabbi Mordochai followed one of its tributaries, 

 and crossed it at the same place where Lenz did in 

 1880, about 120 miles above its mouth. Panet and 

 Bu-Moghdad travelled very hurriedly, with a large 

 caravan coming from St. Louis, on the Senegal, 

 and had no chance for making many observations. 

 In 1828 Caillie ascended its upper part on his re- 

 turn from Timbuktu. Douls intends first to visit 

 Wad Sus, which is situated between the Anti- 

 Atlas and the High Atlas. Rohlfs ascended the 

 valley in 1862, when he explored the upper part 

 of the Wad Draa and the Oasis Tafilet. 



America. 



Letters from Europe give some more particular 

 information of the object of Dr. K. von den Steinen's 

 expedition to Brazil. Three years ago he and Dr. 

 O. Clauss sxu-veyed the whole length of the Xingu. 

 Von den Steinen intends to complete this work by 

 exploring its sources. He will start again from 

 Cuyaba. As on his former expedition geographical 

 researches formed the main object of the journey, 

 he could not make a long stay among the inter- 

 esting tribes of the upper Xingu. Nevertheless he 

 obtained ethnological information of great impor- 

 tance. On the present expedition he proposes to 

 live some time with the Indians of that dis- 

 trict, who have never been in contact with whites, 

 and therefore are of particular interest for eth- 

 nologists. Dr. P. Ehrenreich, who has studied the 

 tribes of Rio Doce, and made valuable anthropo- 

 logical observations during his journey, and the 

 painter Wilhelm von den Steinen, will be his com- 

 panions. This expedition, which consists exclusive- 

 ly of scientists who are thoroughly acquainted 

 with the field of their researches, will yield valu- 

 able results. 



Mr. H. N. Ridley, assistant to the British muse- 

 um, is going to visit Fernando Noronha, the lonely 

 island off the Brazilian coast. The Brazilian gov- 

 ernment has granted him permission to make 

 botanical and zoological collections on the island, 

 though generally visits of strangers are prohibited 

 on account of a colony of convicts being estab- 

 lished there. 



Polar regions. 



Gilder has returned from his journey to Hudson 

 Bay, and given up for the present his plan to reach 

 the north pole by this route. We pointed out last 

 week that the difficulties he would encounter were 

 almost insuperable, and are glad to learn that he 

 reached the same conclusion. Gilder arrived at 



Selkirk, near Winnipeg, March 2. According to 

 his own account, after leaving Winnipeg last fall, 

 he had a very unpleasant voyage to York Factory, 

 occupying two months. He was unable to get a 

 boat all the way, and had to proceed in a canoe, 

 getting Indians to •bring his supplies along. He 

 reached Fort Churchill too late to catch a Hudson 

 Bay boat for Nottingham Island, and, as he would 

 have had to stay several months about Fort 

 Churchill without occupation, he decided to return 

 to New York to transact some business, after which 

 he will leave in time to catch the next Hudson Bay 

 boat, several months hence, or else take a whaling- 

 vessel bound for the northern seas next summer. 

 He left his companion, Griffith, at Fort Churchill, 

 with instructions to take the stores and proceed to 

 Nottingham Island by the first Hudson Bay boat. 

 Gilder promised to join him there. It is to be 

 hoped that he will give up the Hudson Bay route 

 for good, and take a Scotch whaler going to Smith 

 Sound instead . The route from Fort Churchill to 

 Lancaster Sound by boat and sledge is impracti- 

 cable, and ought not to be attempted by an ex- 

 plorer who wishes to visit the extreme north. 



General. 



Charles A. Schott has continued his study of the 

 observations on terrestrial magnetism in America. 

 In his former papers, which were published in the 

 annual reports of the coast and geodetic survey 

 for the years 1880-82, he treated the declination. 

 The present paper — Appendix 6 to the report for 

 1885 — contains a large collection of observations 

 on the magnetic dip and intensity. The collection 

 of data is very complete and clearly arranged, so 

 that it is easy to find the elements of any desired 

 place. It will be of permanent value to the 

 student of terrestrial physics. Schott discusses 

 this large collection of data in order to ascertain 

 the secular change of the magnetic dip and inten- 

 sity, and uses the results of his researches, with 

 due reserve, for the construction of charts of the 

 United States showing the lines of equal mag- 

 netic dip and intensity. His scrutiny of the obser- 

 vations leads him to the conclusion that it is im- 

 possible at the present time to give a detailed map 

 of this kind. The observations of most places are 

 made at too long and irregular intervals, and are 

 not sufficiently reliable. Therefore he gives only 

 a general map of the course of these lines. The 

 belts of stationary dip and intensity, which are in- 

 dicated in the maps, showing the boundary be- 

 tween increasing and decreasing dip and inten- 

 sity, are of special interest. The belt of stationary 

 dip runs through the Strait of Florida^ crosses the 

 Mississippi just above its delta, and then turns 

 again south, passes through central Texas, through 



