[23] 



32 



Again, I observed two slabs — one measuring thirteen feet long, four feet 

 six inches broad, and two feet thick ; the other eleven feet long, six feet 

 broad, and two feet thick — v/hich were split ni two, so as to form slabs of 

 the same dimensions in length and breadth, bnt only one foot thick ; and 

 so perfect were the faces of cleavage, that they did not deviate one inch 

 from a trne level surface. . 



So confident are the quarrymen of the certainty of splitting this granite 

 in any required direction, when even of no greater thickness than nine 

 inches or a foot, that they will, for the sake of having weight and sub- 

 stance in the block to retain it in its position while under the hammer 

 and chisel, first dress the two outside faces^ and trust to splitting the slab 

 or block ni two. 



Fully to appreciate the quality of this granite, the quarries themselves 

 must be visited, and the huge blocks in mass inspected as they are re- 

 moved from tlieir original bed. There, one may see a perpendicular face 

 of nineteen fiset presented to view, extending twenty, thirty, and even 

 forty or fifty feet, without a seam or flaw, or the slightest variation in 

 hue. A mass of forty or fifty tons weight may often be seen severed from 

 the parent rock, by the simple but efficietit means of small iron wedges. 



On some slabs, by close inspection with the magnifying glass, a few 

 minute specks of iron pyrites may be seen ; but none were observed vis- 

 ible to the naked eye. 



Mr. Green thitiks nearly one-third of the freight may be saved by bring- 

 ing the rock to its proper dimensions at the quarry. 



This granite does not spaul freely, but, in consequence of the facility 

 jvith which it splits, but little spauling is required. 



From the bottom of the Waterville branch quarry to the summit of the 

 outburst is forty feet, by barometrical measurement. 



The Fox rock quarry is thirty-six feet from top to bottom, where now 

 excavated. It might be worked some fifteen or twenty feet lower before 

 being incommoded by water. Mortar adheres with such force to this 

 granite, that, when fairly set, it requires as much force to separate the 

 substance of the granite as to detach the rnortar from the face. 



On the whole, the inspection of these granite quarries has impressed 

 me with the belief that no locality can furnish a superior quality of gran- 

 ite, and that it cannot be surpassed for strength and durability by any 

 building-material in the world. 



The stonecutters' bill in granite will, I fear, run up very high, on ac- 

 count of its great hardness ; but, if the expense be not an objection, I do 

 not think that there will be any practical difficulty in rendering in granite 

 ornamental work so little elaboraK; as that of the Norman style. 



An objection to the use of granite for the Smithsonian building deserves 

 serious consideration. It is, that in this material the effect of light and 

 shade is in a great measure lost; while every projecting ornament in the 

 marble is marked by a distinct shadow. How far this may injure the 

 general effect under the plan adopted, the committee will judge. Results 

 of considerable practical importance may be obtained by an accurate 

 chemical analysis, chiefly with reference to the proportion of silica, alu- 

 mina, magnesia, and iron, affecting the durability, discoloration, and ex- 

 pense of working. Time, however, did not permit this investigation. 



All of which is respectfully submitted. 



DAVID DALE OWEN. 



Washington, March 11, 1847. 



