i88 



University of California. 



[Vol. 2. 



San Miguel has a length of about eight miles, and a width of 

 about four. Its two principal peaks, 861 and 850 feet in altitude, 

 respectively, are situated near the center of the island, and separa- 

 ted by a saddle. From these points the surface slopes gently in all 

 directions. Steep cliffs mark the southern side of the island, rising 

 to a height of from 400 to 600 feet along the middle of this side. 

 For a distance of over three miles on this side there is a low and 

 rather broad platform, the rear of which has an elevation of only 

 forty to eighty feet. 



The summit of the island is nearer the southern side, and the 

 longer and gentler slopes are to the north. This side of the island 

 is but slightly dissected, and shows only three definite stream 

 courses for its entire length. Since the gentler slopes face the 

 north, and since the open ocean is on the west, we should expect, 

 on the principles set forth later, to find the greatest amount of 

 cutting on the west and northwest; and, judging from the sub- 

 marine contours, this is the case. For the same reason, the best 

 developed elevated terraces, if any are to be found, must be looked 

 for on the same part of the island. The small U. S. C. & G. S. 

 map has rough indications of terraces on the northern side of the 

 island, besides the low platform on the southern side, and a sug- 

 gestion of terracing near the eastern extremity. On the large 

 contoured manuscript map of the U. S. C. & G. S. (scale 1:20,000) 

 this apparent terrace at the eastern end is seen to be at an elevation 

 of 240 feet. North of the island's center, terrace-like platforms are 

 seen at elevations of 440-480 feet and 520—600 feet. The most 

 pronounced terrace-like structures, however, lie along a line run- 

 ning from the western summit toward the western end of the island. 

 Along this general direction there are nearly level stretches at 220— 

 240 feet, 320 feet, 480 feet, and 560 feet. At 320 feet the nearly 

 level area has a width from front to rear of over a mile; the interval 

 between the 440- and 480-foot contours is three-quarters of a mile, 

 and that between the 520- and 560-foot contours is more than half 

 a mile. In all cases these level stretches are marked by a more 

 rapid rise at their rear. These features certainly simulate terracing, 

 and although the above facts are not sufficient for an absolute 

 statement, there is little doubt in the mind of the writer, especially 



