116 



Land Magnetic Observations, 1911-13 



courteously provided me free transportation as far as Cucuhy, on the Brazilian frontier, 

 which was reached on July 20, the trip being made via the 12-mile Yavita-Pimichin portage. 

 From the frontier to Sant Anna, about 100 miles below Santa Isabel, transportation was 

 secured on small boats, launches, and steamers. At Sant Anna a launch was obtained for 

 the remainder of the trip on down to Manaos, where I arrived on August 16, 1913. 



Following supplementary instructions received at Manaos, the trip to Georgetown, 

 British Guiana, was begun on October 1, and passage was engaged on launches as far as Boa 

 Vista on the Rio Branco. A canoe was used to reach Fazenda "Porre" and the next two 

 stations were reached on foot, the outfit being transported by ox-cart. At Dadanawa, 

 passage for the difficult trip down river, through the rapids to Rockstone, was secured on 

 a large boat paddled by Indians. Wismar was reached by railway and Georgetown by river 

 steamer on December 4. Here the field work was closed. Leaving Georgetown on Decem- 

 ber 6, I reported at Washington on December 18, 1913. 



The total time consumed on the above work was from June 29, 1912, to December 18, 

 1913, or 538 days. Deducting the time spent in travel to and from the field, making 

 arrangements, loss due to sickness, and various delays, in all 219 days, there are left 319 

 days of actual field work, or an average of 3.9 days per station. The travel to and from 

 field totaled about 6,730 miles, while travel in field amounted to about 8,970 miles, making 

 a total of 15,700 miles. This averages 192 miles total travel per station, or 109 miles field 

 travel per station. This last includes the trip of about 1,900 miles from Guayaquil to 

 Caracas with 2 stations en route, and the 490 miles round trip from Maracaibo to Cucuta 

 with 1 station. Counting out these distances, the field average is about 84 miles per 

 station. The distances covered in the field by the various means of transportation were 

 approximately as follows: sailboat, 430 miles; railway, 705 miles; handcar, 65 miles; 

 canoe, 700 miles; coach, 40 miles; muleback, 110 miles; on foot with ox-cart, 90 miles; 

 launch, 2,600 miles; steamer, 4,230 miles. 



No very marked local magnetic disturbances were noted along the west coast, although 

 the sand which occurred everj'where had a very large percentage of magnetite. There 

 appears to be some local disturbance near Mapire on the Orinoco River and a much larger 

 disturbance near San Carlos on the upper Rio Negro. 



During the whole trip I was received, almost without exception, with the greatest 

 kindness and courtesy. The American diplomatic and consular officers rendered much 

 assistance. The Minister of Interior, both of Peru and Venezuela, furnished valuable 

 letters of introduction to their local officials, regarding free entry of instruments, etc. The 

 govermnent of Ecuador instructed its officials at Esmeraldas to render every assistance 

 possible during the special eclipse observations. In the course of the work along the western 

 coast, the managers of the various offices of the Central and South American Telegraph 

 Company were always ready to obtain time-signals and to render other valuable assistance. 

 Owing to their great number, it is impossible to mention by name the many officials and 

 private individuals who extended required aid. 



H. R. ScHMiTT, ON Magnetic Work in Peru, May to August 1912. 



The following work was executed according to instructions received from the chief of 

 party, Mr. J. P. Ault, dated Tarma, May 22, 1912. The instrumental outfit consisted of 

 magnetometer No. 8, dip circle No. 171 provided with 4 dip needles, marine chronometer 

 No. 1044, and watches Nos. 53 and 100. 



The stations at which magnetic observations were made are: 



1912. 



1. Tarma May 23. 



2. La Merced June 4. 



3. Enenas June 9, 10, Aug. 11. 



4. San Nicolas June 14, 15. 



5. Puerto Bermudez June 21, 22, Aug. 4, 5. 



6. Puerto Victoria June 26. 



1912. 



7. Platanoa June 29, .'iO. 



8. Banoa July 5. 



9. Honoria July 7. 



10. Masisea July 14, 20, 21, 22. 



(A repeat station, previously occupied by C. C. Stewart, 

 October 1910.) 



