4o6 The National Geographic Magazine 



Skagway. The many channels between 

 the Fox Islands of the Aleutian Archi- 

 pelago were another object of work. 



A Map of the Philippine Islands on the 



scale of 1 5 miles to an inch is in course 

 of preparation by theU. S. Signal Corps, 

 and will be ready for distribution about 

 January i, 1902. During the past year 

 much new information has been obtained 

 by military and civil expeditions through- 

 out the islands, which will be incorpo- 

 rated in the new map. The map will 

 contain the greatest number of names 

 yet published on any map of the archi- 

 pelago, the spelling in all cases being 

 according to that approved by the U. S. 

 Board on Geographic Names in its re- 

 cent report. The military telegraph 

 lines and cables, commercial and mili- 

 tary telegraph stations, telephone sta- 

 tions, open ports, coastwise ports, and 

 light-houses will also be indicated, as 

 well as the boundaries of the provinces 

 as established by the Commission. 



The Antarctic, carrying the Swedish 

 south polar expedition, sailed from 

 Gothenburg October 16. Prof. Otto 

 Nordenskjold, the leader of the party, 

 states that they will proceed to Buenos 

 Ay res and Tierra del Fuego, and then 

 push as far south as is found possible. 

 When winter comes on a party of six 

 under Nordenskjold will land and spend 

 the winter making scientific observa- 

 tions. The A ntardic meanwhile will re- 

 turn to Tierra del Fuego in charge of 

 one of the scientists of the party, who 

 will conduct researches in that little ex- 

 plored country. Thus, while the Ger- 

 mans are exploring the regions south of 

 the Indian Ocean and the British that 

 south of the Pacific Ocean, Dr. Nor- 

 denskjold and his party will be at work 

 in the regions south of the Atlantic 

 Ocean. Professor Ohlin and M. K. A. 

 Anderson go as zoologists. Dr. Bodman 

 as hydrographer, Dr. Skottoberg as bot- 

 anist, and Dr. Ekolof as medical officer. 



Depth of the Atmosphere Surrottnding' 

 the Earth* — The Belgian Royal Meteor- 

 ological Observatory has published the 

 estimates made by various mathemati- 

 cians and physicists regarding the depth 

 of the atmosphere surrounding the earth. 

 The calculations of the various scien- 

 tists upon this subject recently given 

 in The Scientific American are widely 

 divergent. Biot estimated that the 

 depth was only about 40 miles; Bra- 

 vais, 70 miles; Mann, 81 miles; Cal- 

 landrau, 100 miles; Schiaparelli, 125 

 miles; Marie Davy, 187, while Ritter 

 stated that it reached to a height of 216 

 miles. In Great Britain, during the 

 early part of the last century, the depth 

 of the atmosphere was generally ac- ■ 

 cepted as being 47 miles, but the fact 

 that meteors became incandescent at a 

 much greater altitude proved that this 

 calculation was at fault. Sir Robert 

 Ball states that meteors have been ob- 

 served at a celsitude of more than 200 

 miles; and since they only become incan- 

 descent when they come into contact 

 with the air, the calculation of Ritter 

 appears to be the most correct. 



In Bolivia, in the region that lies be- 

 tween the crest of the Andes and the 

 great Amazonian Plain, an expedition^ 

 equipped and sent out by Sir Martin 

 Conway is continuing his work. The 

 country cannot be called wholly un- 

 known, as large areas have been visited 

 by native prospectors, but it has never 

 been scientifically explored and mapped. 

 It is from the famous gorges of this- 

 region that the Incas obtained much of 

 their gold, and in the fertile valleys 

 is grown some of the best coffee in 

 the world. The leader of the expedi- 

 tion is Mr. Jones W. Evans, a well- 

 known geologist and traveler, who has- 

 made his name known by good work 

 done in the western part of Brazil. With 

 him are an assistant geologist, a sur- 

 veyor, a botanist from the United States, 

 and a zoologist. They hope to make 



