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Memoir on the Geology of the 



[Oct. 



" the workmen would use imperfect stones in works requiring weight 

 t* and strength. The larger annicuts are from twelve to fifteen 

 " paces across, with ample room for abundance of perforations of this 

 " kind. If I recollect right, the people of the annicut told me, that the 

 " excavations or holes were occasioned by the working of the stones 

 " detained within them."* 



Before concluding the description of these cavities in India, I must 

 be permitted to detail the position, form, &c. of one or two of them, as 

 they correspond so precisely with those described by authors as found 

 in Europe. The largest of the cavities of Makoortee is a treble one, 

 that is, composed of three nearly in a line, their respective levels de- 

 creasing. They had evidently been separate, until, increasing in size, 

 they joined into one, the thin lip of separation having been worn out (dia- 

 gram, Nos. 9, 10, 11). The depth of this triple perforation is three feet, 

 and the length of the three together more than eight feet. Specimen 

 No. 1/5 is a pebble from this cavity ; one or two in the middle perfora- 

 tion must have weighed more than a hundred pounds. Ascending the 

 river about three hundred yards, there is another slab, larger than the 

 one just mentioned, nearly in an horizontal situation, on the surface of 

 which I counted eight excavation;; ; none however of the same magni- 

 tude as those lower down. They were sufficiently characteristic to 

 show their origin. About fifty yards higher, in another horizontally 

 placed mass, I remarked a double perforation, that is, two joined into one. 

 In the bed of the main branch of the Pykara river about a mile below 

 the place where the tents are usually pitched, is another nearly hori- 

 zontal mass, with seven cavities on a rather smaller scale, one of which 

 is double, the largest not exceeding ten inches in diameter, and the 

 smaller hardly three inches ; the remaining five were all in a forming 

 state. In this spot, I observed a flat block, on the edge of which was 

 a pretty large perforation, one side being wanting, owing to having 

 been worn out to the bottom, probably from the same causes that pro- 

 duced the erosion of the brims of the double and treble cavities. I am 

 particular in noticing this last perforation and its form, since it appears 

 to me to be perfectly analogous to that described by De la Beetle, which 

 I shall have occasion to advert to hereafter. Captain MacLean, who 

 was with us at Makoortee and saw the erosions which we have de- 

 scribed, informs me that some weeks after, while riding with the Right 

 Honourable the Governor, along the banks of the Pykara river, about 



* All this is sufficient evidence to prove that there is even no occasion for the little cavi- 

 ty, which I supposed might have been left by the decomposed nest of hornblende ; but a 

 small depression in the rock, a seam, a fissure, or in the case alluded to in the diagram, 

 the junctures of different rocks, although contiguous, may be sufficient to give cause and 

 commencement to the erosions, and the existence of the same cavities in annicuts, made 

 Of bricks, confirms more and more what we have stated. 



