Aug. 1845.] Proceedings of the Asiatic Society . lxxxv 



letter forwarding- a map constructed by Lieut. Sherwill, 66th B. N. I. which has been 

 laid before his Excellency. 



I am at the same time desired to state that the Governor General considers the map to 

 be admirably executed, and that Lieutenant Shei-will deserves great credit for devoting 

 his leisure hours to scientific pursuits, and for presenting to the Asiatic Society the result 

 of his exertions. 

 I beg to return Lieut. Sherwill's map, and to remain, 



C. S. Hardinge, 

 July 30th, 1845. P. S. 



On application to government we have been kindly favoured with a set of the 

 Revenue Survey maps of the Lower Provinces as far as completed, being in all, as per 

 accompanying list, 131 sheets. The constant references which we have to make for local- 

 ities render these maps together with those of the North West Provinces formerly obtain- 

 ed, of much value to us. 



Museum of Economic Geology. 

 We have had referred to us a specimen of (Assam 1) Lignite by Messrs. Mackey, the 

 examination of which is worth putting on record, as adding one more to those tabulated 

 by Mr. James Prinsep, it is as follows : — 



Report on a specimen of Lignite (sent as coal ) for examination to the Museum of Econo- 

 mic Geology. 

 This specimen is not coal but lignite, i. e. wood reduced to carbon, and often impreg- 

 nated with other matters, as iron, silex, &c. The locality whence obtained is not men- 

 tioned and I may note here that it always should be so. The clay and sandstone sent 

 witli it resemble those of Assam. 



Its specific gravity is 1.34 



It contains in 100 parts. 



Water, 12'00 



Carbon, 3L60 



Volatile matter, 26*40 



Ash, 29*20 



99-20 

 Loss. 80 



100.0 

 It is thus a poor ferruginous, silicified lignite, the ash being principally iron and silex, 

 but it may, in common with many of the lignites, be a very good fuel for many purposes 

 as where heat only or carbonaceous matter (as in smelting metals) be required, but 

 where flame, as for steam engines is also desired it would probably be insufficient. 

 Nothing, however, can be said on this head but from a large and proper furnace trial. 

 It might in some cases be profitable to mix with good coal. 

 The lignites are in some countries of Europe used as manures both pure and burnt. 



H. PlDDINGTON, 



Cur. Mus. Eco. Geology. 

 We are indebted to Major Glover, of the Madras Engineers, for three boxes of speci- 

 mens ; his note of them is as follows : — 



