1146 Asiatic Society. [No. 107. 



*' XVI. Architectural Geology — Stones employed for Architectural or Engineenng pur- 

 poses ; Ornamental Stones, as Marbles, S^c. — Of these the collection contains but one or 

 two specimens. We have many of cornices, capitals, and images, which would afford 

 much instruction, though the antiquity of but very few of them can be known 

 The conditions of climate here are so different from those of Europe, that it may 

 be difficult to establish correct comparative views, though we need not on that 

 account neglect European specimens, and the results of their experience. We 

 require however, more especially, specimens of stones, bricks, and marbles from 

 ancient Indian buildings and fortifications ; with, of course, the dates of their 

 erections, when these can be ascertained. These it should be remembered are 

 desirable both when they have well, and when ill withstood the effects of the 

 climate ; for both are lessons to the architect. It should be carefully noted if 

 they appear ever to have been protected by plaster, paint, or casing j specimens 

 from more recent erections, particularly where exhibiting signs of early decay, should 

 not be neglected. The tomb-stones of the early European settlements might 

 perhaps afford good practical lessons in this respect. The church of Bandel bears, 

 I think, the date of 1680, and it is possible that many tombs of at least a century 

 old, might be found, either European or native, of various materials. 



*' The foregoing remarks hold good for the ornamental stones and marbles. Our 

 Museum affords a very few of these, and a geological series of specimens from 

 the sandstone quarries of Chunar, by Captain Franklin, 



" XVII. Mortars and Cements. — We have nothing of this kind in the collection, nor 

 in the Museum, as far as I have yet seen ; but the field which these afford for curious 

 and profitable research, and the great public and private advantage to be derived 

 from a thorough investigation of it, is immense. It would appear that many of the 

 native cements of former times were, like those of the ancient Romans, even more 

 durable than the brick or stone with which they were used, and very far superior to 

 any thing which can now be made, even with the greatest care. It is then, well 

 worth our attention to procure also from the ancient buildings, both of India and 

 Europe, specimens of the mortars and cements. All the limestones which can be 

 obtained, from the kunkurs up to the pure marbles, are of course desiderata, as 

 being the raw material of the cements. I should add to these, specimens of the 

 corals, and of the fresh and salt-water shells so extensively used for making lime in 

 India. We are quite ignorant as yet of what may be the effect of mixing the shell 

 and stone limes in various proportions ; of what is owing to the Silica alumina, and 

 oxides of iron in the kunkurs, to the phosphates (from the shells or the iron of the 

 kunkurs) and to all these with the various proportions of lime and magnesia, which 

 iorm the bases of the cements. These are great objects of research, for which 

 the first requisite is to have series of specimens at hand ; without which they 

 must always be imperfectly examined, and most frequently will not be so at all. 



'• XVIII. Materials fw Road Ma/cin^.— These, 1 need not say, are of primary 

 importance. It is true that expence frequently prevents their being carried far, 

 though sometimes a road may carry the materials for its own extension. But 

 there is another point of view in which the collection of both good and bad 

 materials for road-making may be important, when the subject comes to be 



