HOLMES.] CAVE-TOWN, EIO SAN JUAN. 389 



upon the question of antiquity. If we suppose the recess to be destroyed 

 is six feet deep, the entire cliff must recede that number of feet in order 

 to accomplish it. If the rock were all of the friable quality of the mid- 

 dle part, this would indeed be the matter of a very few decades ; but it 

 should be remembered that the upper third of the cliff- face is composed 

 of beds of comparatively hard rocks, sandstones, and indurated shales. 

 It should also be noted still further that at the base of the cliff th^re is 

 an almost total absence of debris, or fallen rock, or even of an ordinary 

 talus of earth, so that the period that has elapsed since these houses 

 were deserted must equal the time taken to undermine and break down 

 the six feet of solid rock, plus the time required to reduce this mass of 

 rock to dust ; considering also that the erosive agents are here unusually 

 weak, the resulting period would certainly not be inconsiderable. 



Figure 2 gives a fair representation of the present appearance of these 

 dwellings, while their relations to the group of ruins above will be 

 understood by reference to Figure 1. These ruins are three in number — 

 one rectangular and two circular. The rectangular one, as indicated in 

 the plan C, is placed on the edge of the mesa, over the more northern 

 group of cave-dwellings; it is not of great importance, being only 34 

 by 40 feet, and scarcely 2 feet high ; the walls are 1 J feet thick, and 

 built of stone. 



The small tower B is situated on the brink of the cliff, directly above 

 one of the principal groups of cave-houses. It is neatly built of stone, 

 which, although not hewn, is so carefully chosen and adjusted to the 

 curve that the wall is quite regular. That the stone was procured from 

 the neighboring cliffs is indicated by the presence of great numbers of 

 characteristic fossils. The wall is 18 inches thick and from 2 to 6 feet 

 in height. 



Long' lines of debris, radiating from all sides, indicate that it has 

 been much higher, and has but recently fallen. This tower is enclosed 

 by a wall, also circular in form, but open toward the cliff, as seen in the 

 drawing; the ends projecting forward and irregular and broken as if 

 portions had fallen. Its construction is like that of the inner wall, but 

 the height is not more than 3 feet at any point. The diameter of the 

 inner circle is 12 feet, that of the outer 22 feet ; the distance, therefore, 

 between the walls is a little less than 4 feet. In this space there are 

 indications of partition-walls that have originally divided it into a num- 

 ber of apartments. 



About one hundred and fifty yards to the southwest of this ruin are 

 the remains of another similar structure. It has been, however, on a 

 much grander scale. The walls are 26 inches thick, and indicate a 

 diameter in the outer wall of about 140 feet. They are not above 4 feet 

 high at any point, and in the parts toward the cliff can only be traced 

 by a low ridge of earth. The remaining fragments of wall are at the 

 remoter parts of the circles, and are in every respect like the walls 

 already described. The inner wall, which can be traced but a short dis- 

 tance, is 8^ feet from the outer, and has been connected by partition- 

 walls, as in the other case. 



The first impression given by this curious enclosure is that it was 

 designed for a "corral", and used for the protection of herds of domes- 

 tic animals; but since these people are not known to have possessed 

 domestic animals, and when we further consider that en closures of pickets 

 would have served this purpose as well as such a massive and extraor- 

 dinary structure, we can hardly avoid assigning it to some other use, 

 which use, doubtless similar to that of the smaller tower, is very natu- 

 rally suggested by its location and construction. 



