786 Museum of Economic Geology [^No. 118. 



7. The next department of the Museum, on the arrangements of 



which I would make a few remarks, is that of 

 Arrangements of . , .^ , i /-t -i t-, . . . , . , 



the department of Architecture and Civil Engineering; in which are 



Civil'EngTn^eerin^g"'^ included the various applications of the rocks com- 

 posing the earth's crust, to the purposes of common 

 or hydraulic architecture ; of road-making, in the formation of mortars 

 or of cements. Since each of the great systems or series of rocks, 

 formed the distinct epochs that have been recognised by geologists 

 furnish materials adapted to some of the preceding objects, it would 

 be well to place in the Museum, a suite of characteristic specimens of 

 the individual rocks composing these systems, arranged according to 

 that order of superposition, which has been found to prevail among 

 them in nature. It is, however, to be remarked, that those lithological 

 characters of rocks, on which their applicability to the purposes of the 

 architect and engineer is dependent, vary so much in different loca- 

 lities, that although a particular rock may, in one country, be admir- 

 ably adapted to such purposes, it by no means follows, that its equi- 

 valent in another, must be equally so. Hence, although it would be 

 useful in aiding research, to have in the Museum such a collection 

 of specimens as I have above averted to, yet in this department our 

 chief object should be to procure, with the least possible delay, a col- 

 lection of native, not exotic rocks. It is by the investigation of the 

 physical and chemical properties of the former, that information avail- 

 able for practical purposes in this country, is to be procured ; and 

 although comparison of these results with others obtained elsewhere 

 would, of course, be interesting, and in time might be instituted, 

 it is I consider, of secondary importance. Specimens, therefore, of all 

 natural products, employed in the department of Public Works, 

 whether as building materials, road materials, or materials for making 

 mortars and cements, ought to be procured for the Museum, and their 

 properties experimentally investigated. 



Considering the extent to which Public Works are now carried 

 on, and the number of intelligent individuals employed upon them, 

 it cannot be doubted that a large amount of information, speci- 

 ally relating to the department of Economic Geology under no- 

 tice, exists in the community ; and were the Museum established, 

 it would prove the means of concentrating this for general bene- 



