March, 1844.] Proceedings of the Asiatic Society. xxvii 



Rajmehal Canal is to pass, with the supposed limits of the Gangetic Alluvium. I do not 

 know if any Geological Report was made on this interesting tract of country, but shall 

 not fail to enquire and to obtain its publication if possible.* 



Mr. Black has obliged us with a Report on, and impressions from, the Lithographic 

 Stones sent down by Captain Shortrede. 



H. Piddington, Esq. 



Dear Sir, — In reply to your note of this morning I beg to inform you, that Mr. 

 Blechynden has received the copy of the Moulmain Almanac intended for the Asiatic 

 Society's Rooms ; and with reference to the Stones, I have pleasure in forwarding two 

 proofs taken off from impressions on each, but regret much I cannot give you so favor- 

 able an account of them as some of the former ones, as I find Nos. 1, 2, 3, 4, 5, 6 and 

 7 too soft, and No. 8 too hard, more resembling marble. This last is one of the two you 

 left with me, before those you left in the box. The little blue piece is by far too soft. 



Asiatic Lithographic Press, Thos. Black. 



No. 3, Hare Street, 1th March, 1844. 



It would thus appear, that none of these are equal to the former fine specimen, as 

 might well occur when a number are taken at random from a heap of fragments 

 quarried for building purposes ; for in the German quarries also it is only from certain 

 beds near Munich that the fine Stones are procured, and it is to this that, in part, their 

 high price is owing. This matter however, is well worthy of a special recommendation to 

 Government from the Society, since we are certain that a really good Stone exists, 

 and have so near the spot an active, intelligent and zealous co-operator, like Captain 

 Shortrede. 



I have added to our collections specimens of the common Corundum Stone of 

 the Bazar, with the powder of which all the cutting, grinding and polishing work 

 of precious Stones is performed; even the Diamond is averred to be cut and polish- 

 ed by it, and it seems certain, that the use of Diamond powder is not known to the 

 natives ; or if known, that its expense prevents its adoption, or that the Indian lapidary 

 finds his own process practically the best. 



I find upon trial that the Corundum, would certainly cut every thing below the Sap- 

 phire in hardness, and no doubt polish the Sapphire, and I believe that if better known 

 in Europe, it would be found of high value in the arts, and in many instances, 

 (I speak here upon very competent authority,) reduce the prices of many very expen- 

 sive processes, such as that of grinding hard steel pivots and plates, gems for lenses and 

 the like, for which only Diamond powder can now be used, and the expense of this is 

 often completely a prohibition on its employment, or adds enormously to the cost of the 

 article. 1 have placed upon the table from our own collection nine specimens of the 

 Stone, beginning with the Emery of Naxos, and ending with the crystallised rose 

 Corundum of Ceylon. 



* I have since learned from Colonel Forbes that no Geologist was attached to the Survey. Bor- 

 ings were made, and wells sunk along the line, and a series of specimens also collected from the 

 adjacent rocks, but it is not known what became of them ! 



