294 The National Geographic Magazine 



Copyright, 1903. by A. W. McCurdy 



Tetrahedral Kite in the Air 



magnetic pole, from which not only an 

 accurate location of the magnetic pole 

 may result, but other most important 

 results will follow. The determination of 

 the north magnetic pole by Captainjames 

 Clark Ross, in June, 1831, rested on a 

 single determination. Owing to local 

 disturbances, which may be expected in 

 that region, there is no telling how close 

 his determination was to the actual mag- 

 netic pole. His position was on Boothia 

 Felix, in north latitude 70 05' 17" and 

 west longitude 96 45' 48". 



It is generally believed that the mag- 

 netic pole is subject to a fluctuation in 

 its position, and it is hoped that Amund- 

 sen's work will throw some light upon 

 the rate and direction of motion. 



THE TETRAHEDRAL KITE 



THE accompanying illus- 

 tration shows one of 

 Dr Alexander Graham Bell's 

 tetrahedral kites in the air. 

 It was received after the June 

 number of the National 

 Geographic Magazine 

 went to press. The kite is 

 the sixty- four-celled tetrahe- 

 dral kite shown as D in figure 

 16, page 227 of the June 

 number. The illustration 

 shows the kite flying at the 

 proper angle. The photo- 

 graph was taken at Colonial 

 Beach, Virginia, Ma}- 26. 

 1903, by Mr A. W. McCurdy. 



PORTO RICO AND THE 

 UNITED STATES 



PORTO RICO is now fur- 

 nishing a market of a 

 million dollars a month to 

 the producers and merchants 

 of the United States, and sup- 

 plying nearly a million dol- 

 lars' worth each month of 

 tropical products required by 

 the United States. 



These figures of commerce 

 between Porto Rico and theUnited States 

 are in marked contrast with those of 

 earlier years. In the fiscal year 1898, 

 which immediately preceded the transfer 

 of Porto Rico to the United States, the 

 exports from the United States to that 

 island were $1,505,946. In the next 

 year they were $2,685,848 ; in 1900, 

 $4,640,449; in 1901, $6,965,408; in 

 1902, $10,882,653, and in the year 1903 

 will be about $12,000,000. Thus the 

 total shipments from theUnited States to 

 Porto Rico for 1903 will be eight times 

 as great as those of 1898, and six times 

 as great as those of 1897. On the other 

 hand, shipments from Porto Rico to the 

 United States have grown from $2,414, 

 356, in 1898, to $8", 378, 766, in 1902, and 



