1 836.] 



JN eelgherries and Koondahs, 



291 



seen and examined all we wanted, we began our descent. In a deep 

 ravine which descends from the top of the hill to the right of Ma- 

 koortee peak, through which a large torrent runs, there are three beau- 

 tiful cascades, one some hundred yards below the other, which precipi- 

 tate their waters over the ledges of the hornblende slate. At all these 

 places the horizontal stratification of the rock is more clearly seen than 

 any where else in this group (No. 170); it contains fewer garnets than 

 that of the peak, and some strata are formed of hornblende only 

 (No. 171). 



We at last reached the foot of this hill where the perforations, before 

 alluded to, are found ; an interesting geological phenomenon, which I 

 hope will throw light in the explanation of similar appearances in some 

 parts of Europe, regarding the origin of which geologists still disa- 

 gree. I will describe those of Makoortee first, and then mention the 

 analogous ones found in Europe, but at present in a different position 

 from those of Makoortee. 



At the foot of this hill is a river, or rather torrent, having its origin 

 in the declivity of the same hill, three or four miles above, the erosions 

 we are going to describe, and, after a short course, discharging its waters 

 into the principal branch of the Pykara river. Along the upper part of 

 its course (which does not exceed five miles) its bed abounds with large 

 slabs of hornblende slate, sometimes inclined, over which the water 

 forms cascades ; at other times they are nearly horizontal. About a 

 hundred yards north of the place where our tents were pitched, there is 

 an oblong mass of the latter description, sixty feet long and thirty-six 

 feet broad. The rock contains hardly any garnets, and the two usual 

 minerals differ in their proportional quantities in different strata 

 (No. 172). The direction of the strata is E. N. E. and W. S. W., and 

 here, as in other localities, it imbeds nests, or oblong pieces, of gra- 

 nular hornblende, with a few grains of felspar (No. 173), which being 

 more liable to decomposition than the rock containing them, like 

 mica in gneiss, and hornblende porphyry in sienitic granite, fall out, 

 leaving cavities, on the exposed surface of the rock, proportionate to 

 the size of the nest. 



Looking at the surface of this slab, which has one or two fissures at 

 an angle with its length, being rather the enlarged seams of the rock 

 than splits, we observe that it is perforated by seventeen cavities, of 

 different dimensions and shapes; their general form, however, is 

 circular, or nearly so, most of them containing numerous rounded 

 small blocks, pebbles and sand. Some of these cavities are situated 

 in the middle of the torrent, others at its sides ; their shape and rela- 

 tive situations, are represented in the diagram (PL 7> fig- 5). Some 

 are convex, the internal circumference being wider than that at the 

 aperture, somewhat like a chatty. At the time I first visited these 



