A GEOGRAPHICAL SKETCH OF THE JUAN FERNANDEZ ISLANDS 93 



late in the season and much of the island was hidden by clouds.' Though some 

 corrections could be made along the south coast and around Cumberland Bay, 

 the result was not what I had hoped for. A second attempt was planned, but had 

 to be given up, and the work was discontinued. Fortunately the Swedish engineer 

 Mr. Bertil Frodin, then a resident of Santiago and a most helpful channel during 

 my negotiations with the authorities, had been invited to join the first flight, 

 and his series of Kodachrome pictures, most of them taken from the plane, was 

 graciously put at my disposal. They have proved to be of very great help; the 

 reproductions here will, I dare say, testify to their high value. A comparison 

 with our photographs allowed me to identify practically every single forest patch 

 shown, and their size and shape was almost the same in 1952 as in 1917. With the 

 aidf of all this material a new sketch map, reproduced here in reduced size, was drawn 

 {fig. i). I want to emphasize that this map is a sketch only. 



Main geographical features. 



Masatierra can be inscribed in an obtuse-angled, isosceles triangle with the 

 hypotenuse (the distance from Pta Isla to Pta Hueso Ballena) 12.5 nautical miles 

 (23 km) long on the sea chart and the greatest width (from Pta Salinas to Los 

 Chamelos) 4.2 miles (7.8 km); circumference 34 miles (=53 km), area 93 sq. km. 

 These are the figures generally quoted, but others are also found: length 15.5, 

 width 3.75 miles (Lopez), 22 and 8 km (Ermel), 25 and 9 km (Branchi), etc. The 

 figures obtained from my map are: length ( = hypotenuse) 18.5 km, width 7 km, 

 area 75.2 sq. km. 



Masatierra is a deeply eroded and very rugged mountain range (fig. 2) rising 

 abruptly from a submarine ridge running S — N and bordered by deep water; the 

 bathymetrical conditions will not be discussed here. There is hardly any level 

 land on the island worth speaking of. Where the soil is not covered by forest, 

 as on the barren seaward slopes of the valleys, on the coast escarpments and 

 on the precipitous ridges rising high above the continuous forest cover, hundreds 

 of lava beds overlying one another can be distinguished, varying in thickness 

 from a few m (in cases less than one) up to 20 or more (Quensel 2 p. 40). The 

 location of the main summit ridge and, as a consequence, the trend of the val- 

 leys, depends on the dip of the lava beds. From the east highland to Mt. Yunque 

 and from Pta San Carlos to Co Alto, the tilt is N to NE, above Pto Frances 

 14 — 18° (fig. 13), at Centinela and Pangal about 20°, between San Carlos and Pto 

 Ingles 12 — 13° (fig. 3), at Co Alto 20° or a little more. From the east end to in- 



' One of Mr. Frodin's photographs of Masatierra seen from the air in 2 000 m altitude 

 was reproduced in the daily paper "Dagens Nyheter". The explanation says: ". . . covered with 

 white clouds that later lifted, enabling us to map the islands accurately". And in the text we 

 read: "We flew to and fro over Masatierra and took series of photographs which will be put 

 together to form maps in scale i: 15000. We had the good luck to get the summits quite free 

 from clouds . . ." This story is confirmed by Mr. Frodin's kodachromes which show the central 

 and northern parts of Masatierra very clear. On the aerial map in i : 28 500, submitted to 

 me by the Chilean Air Force, the island is, however, more or less covered with clouds, and 

 not one of the conspicuous mountains could be identified with certainty. 



