604 REPORTS OF THE BUILDING COMMITTEE. 



State, should they desire information as regards my ability to perform any engage- 

 ments I may enter into. Please address me at this place if you wish me to go on to 

 the city of Washington. 



Very respectfully, your obedient servant, 



SAM'L M. LEIPER. 

 To the Building Committee op the Smithsonian Institution. 



Laid on the table. 



The chairman submitted, from Dr. David Dale Owen, the following report on the 

 Baltimore county quarries : 



To the Building Committee of the Smithsonian Institution : 



Gentlemen : In conformity with your instructions, I have examined a number 

 of quarries in the vicinity of Baltimore, and also one at the Point of Rocks, with a 

 view to ascertain the extent and quality of the building material they furnish, and 

 report as follows : 



Extensive quarries of white crystalline marble commence about twelve and a half 

 to thirteen miles from Baltimore, near a small village called Texas, or Clarksville, on 

 the line of the Susquehanna railroad. 



The first quarry visited is that owned by Pell and Robinson, who are largely 

 engaged in lime burning. It lies on the west side of, and only a few paces from, the 

 main track of the railroad. The surface layers are, by barometrical measurement, 

 forty feet above the level of Cold Spring creek, a small stream running through this 

 quarry ; and ledges of marble extend down to the banks of that stream and form 

 its bed ; varying, however, at different heights, somewhat in texture and appearance. 



The purest variety in this quarry is of a coarse and highly crystalline structure, 

 varying in tint from a pure white to a faint shade of bluish or grayish white, as may 

 be seen by inspection of the various specimens. It is known to the quarrymen under 

 the name of " alum limestone." 



The course of this purer variety is northwest and southeast, with an average width 

 of 150 feet, and extending 525 feet back to Pell and Robinson's west boundary line. 

 Taking the average depth of this quarry at 18 feet, its solid contents may, therefore, 

 be estimated at 18 X 150 X 52 5 = 1,417,500 cubic feet, or 56,700 perches, in this 

 single quarry. 



North of this white crystalline marble, the rock gradually assumes a shade of blue 

 or gray, as may be observed by inspecting specimen No. 4. 



The upper layers at Pell and Robinson's quarry are banded with light gray veins. 

 Below this are at least three feet of pure, highly crystalline, white limestone. Judg- 

 ing from specimens detached from the inferior projecting layers, there is evidently a 

 great body of the same kind of rock beneath, with probably some banded beds, sim- 

 ilar to the upper beds previously described. 



On the east side of the railroad and close to it, some four hundred or five hundred 

 yards from Robinson and Fell's quarry, Griscom and Borrough have opened quar- 

 ries. The rock here is of the same character as that in Robinson and Fell's quarry, 

 and equally good ; see specimens Nos. 2 and 2a. Some nests in this quarry are of a 

 closer grain than the main beds ; see specimen No. lab. 



Theledges of this rock, wherever it projects through the soil, and has been exposed 

 probably for ages, have a dark appearance on the surface, apparently from incrusta- 

 tions of lichen ; but when broken, the discoloration is seen to be superficial, not 

 extending at all into the substance of the rock ; see No. 5b. 



The dip of the beds seems to be generally to the southwest, at an angle of perhaps 

 20° to 25°. 



There is no difficulty in draining these quarries, since there is twenty to forty feet 

 of rock entirely above the level of water drainage. 



The top layers are sometimes in detached and more or less rounded masses ; owing, 

 no doubt, to the corrosive influence of water containing carbonic acid, or some 

 organic acid, percolating through the superficial soil, corroding and dissolving the 

 accessible edges of the calcareous layers. 



Over the upper beds lies usually ferruginous earth of deep red color, forming a 

 remarkable contrast to the snow-white marble beneath ; indeed, this appearance on 

 the surface might, perhaps, often serve as a guide to the detection of the white mar- 

 bles of this region. 



Symington's quarry lies in the same vicinity, about three hundred to four hundred 

 yards from the main track. The owner of this, as well as the other quarries here,, 



