Observers' Field Reports 195 



generally conceded that to go from Corumba to Guayara Mirim would cost about $2,000, 

 which would include the hire of a launch up the Paraguay River to Sao Luiz de Caceres, 

 the cost of the overland journey by mule train to Matto Grosso, and finally the purchase 

 of a boat with the wages and subsistence of the necessary crew for the trip down the 

 Guapore and Mamore" rivers. The regular boat up the Paraguay River runs only at 

 long intervals, and, as the current is too strong for a canoe, it is necessary to hire a launch. 

 After some delay in trying to obtain one at reasonable terms, a launch was finally 

 chartered, on which I left Corumba July 4 and arrived at Sao Luiz de Caceres July 9, 

 where arrangements were made for the overland trip to Matto Grosso. A delay of over 

 a week was occasioned in trying to hire mules. Those finally secured were in such poor 

 condition that they took 4 days longer than should have been necessary. 



Having arrived at Matto Grosso on July 28, I immediately began preparations for 

 the long river journey to Guayara Mirim by way of the Guapore" River which for a long 

 distance forms the boundary between Brazil and Bolivia. There are no launches by which 

 to make this trip, and boats can not be hired on account of the great distance. It is, 

 therefore, necessary to buy a boat, and I was advised that a fairly large boat was desirable 

 on account of the sudden winds that sometimes arise on this large river. As the pro- 

 posed route was down-stream, a large crew was not required, and 2 Indians, beside 

 myself and an assistant who had been engaged to accompany me from La Paz to Manaos, 

 were sufficient. 



I bought the boat, and on July 30 we began paddling the 1,200 miles to Guayara 

 Mirim, where we arrived on September 13. With the exception of the rapids at the 

 Forte Principe do Beira, the river was easily navigable throughout the length traversed. 

 In the upper and lower stretches the ordinary precautions against surprise and attack 

 by the Indians are necessary. During the 45 days required to make this journey from 

 Matto Grosso to Guayara Mirim, 1 1 stations were established. We paddled at an esti- 

 mated rate of about 3 miles per hour usually for about 10 or 12 hours each day, though 

 sometimes for much longer, making as high as 60 or even 65 miles in one day. Since 

 villages or trading settlements are not numerous, the stations were established at suitable 

 intervals as desirable places were found. These stations are, therefore, referred to by 

 number. From Guayara Mirim we traveled over the Madeira-Mamore Railroad to 

 Porto Velho, where a launch was hired for the trip down the Madeira River to Manaos. 

 We left Porto Velho on September 23 and arrived at Manaos October 16, having been 

 delayed somewhat through the necessity of stopping each day in order to chop wood for 

 fuel for the launch. 



After concluding the work at Manaos, I proceeded down the Amazon by steamer 

 to Para, where opportunity was afforded during a delay caused by war conditions to 

 reoccupy the secular-variation station at Pinheiro. I arrived at Bridgetown, Barbados, 

 November 9, and took passage on the same day for New York, no time being available 

 for reoccupation of the magnetic station. 



The total time occupied in the establishment of the 57 stations from my departure 

 to my arrival in Washington was 260 days, with an average field time per station of about 

 4 days. The total distance traveled was about 12,600 miles, of which about 7,810 miles 

 was travel to and from the field, leaving 4,790 miles travel in the field. The average 

 field travel is accordingly 84 miles to the station. The average field expense for each of 

 the 57 stations was about $85. 



The magnetic conditions encountered were generally good, but it would seem that 

 the region about the 200-mile stretch of the rapids of the Madeira River and the rapids 

 at the Forte Principe do Beira on the Guapore" River is somewhat disturbed, due to the 

 volcanic rock which underlies this whole region and crops out at the various rapids. 



