REPORTS OP THE BUILDING COMMITTEE. 665 



of a mile, and is situated on the south side of Kocky run, close to the road which 

 leads from the Island to Captain Towson's. This quarry affords a tolerable freestone, 

 (see specimen No. 29,) hut it has spots and streaks in it, and is of rather a coarser 

 texture and not so uniform in color as the Island quarry. 



About one mile further on the same road, and distant about a mile and a half from 

 Aquia creek, on the north side of Kocky run, is Towson's Beech quarry, which has 

 been wrought to a considerable extent, and has, as most of the .quarries here, a fine 

 face on it, all having been worked on the old-fashioned plan of " grooving " and 

 << lofting," as heretofore described. The rock at this locality is of a very fair quality ; 

 little inferior to Symington's Island quarry, (see specimen No. 30,) and well situated 

 as regards drainage and covering for quarrying. Occasional clay and ferruginous 

 spots are visible ; but a large supply could probably be obtained here, by proper 

 selection, free from any very unsightly flaws or blemishes. 



Half a mile further on, or two miles from Aquia creek, on the south side of Eocky 

 run, is Eobinson's quarry, the property of Mr. Galehorn. 



It will be observed, by specimen numbered 31, that the texture of the rock at this 

 place is rather finer, and the color more of a buff, than at the previously described 

 quarry. 



Two and a half miles from Aquia creek, and distant about half a mile to a quarter 

 of a mile from Captain Towson's house, is another quarry of freestone belonging to 

 that gentleman. The beds here are free to work, but much more interlaminated or 

 leafy in structure, than any of the quarries examined, and certainly less durable, 

 (see specimen No. 32.) The face of this specimen on which the number stands, gives 

 a good idea of the tint which this rock acquires by time and exposure. 



On Jackson's branch of Rocky run, from a mile to a mile and a half south from 

 the island, is a bold quarry, owned by Peggy Norman. The rock here is no doubt dur- 

 able, but exceedingly indurated, and would be nearly as expensive to cut as granite, 

 (see specimen No. 33.) 



Besides the quarries here enumerated, various others have been opened on both 

 sides of Rocky run, of similar quality and appearance to those already described. In 

 fact, every hill for many miles in this neighborhood is composed of solid beds of free- 

 stone, varying in texture from a conglomerate and even pudding stone, to a fine- 

 grained rock similar to number 26, and varying in shade from a yellowish brown and 

 a buff color, to a nearly pure white. It is probable enough, that as new quarries are 

 opened a better material may be found than any yet disclosed. 



In none of the quarries visited in Stafford county did I observe red and pink free- 

 stones like those of Seneca creek. Neither did I see there any of those schistose beds, 

 with green cupreous incrustations, such as occur in the sandstone formation of the 

 upper Potomac, in the cupferschiei'er of Germany, the copper States of England, and 

 the Permian system of Russia. On the geological charts of this region, these free- 

 stones are designated as of the same age as the red sandstones of the Connecticut 

 valley and New Jersey. They differ from these materially in lithological character, 

 and apparently in associated minerals, so far as I have had opportunity of judging ; 

 nevertheless, they may be cotemporaneous ; this can be ascertained only by a careful 

 search after organic remains, which time did not permit. 



On my return to the watering station on Accokeek, I stopped at Major Brooks' 

 for the purpose of seeing a quarryman who has had long experience not only in the 

 quarries of Aquia and Accokeek creeks, but also in the marble and granite quarries 

 of the eastern States. 



He informed me that at seven miles from the mouth of Aquia creek, close to the 

 railroad, at the high bridge on Potomac run, there are solid ledges of freestone in an 

 escarpment of 90 feet ; and according to his statement, there is at that locality a bed 

 very similar in texture and color to that previously described as owned by Syming- 

 ton. Unfortunately, it lies deep seated, and would require a stripping of about 15 

 feet to get at it ; but he says that the strata rise, as you proceed up the Potomac run, 

 to the west, and that there is reason to believe that the ledge in question can be found 

 near the surface about a quarter of a mile from the railroad. If it remains of uni- 

 form texture for that distance, a material not inferior in quality to the best rock on 

 the island might be quarried there more convenient to transportation, and in a much 

 more healthy situation, than on the island, surrounded, as that locality is on all sides,, 

 by low marshy plains. 



On questioning this man with regard to the comparative expense of quarrying 

 freestones there and on Seneca creek, he confidently asserted that by a judicious mode 

 of drilling and very careful blasting, rock might be quarried even cheaper lure than 

 on Seneca creek, although at the latter locality the beds, being thinner and of a less 

 "livery" nature, can be easily split by the "plug and feather," because on Aquia 

 and Accokeek creeks, and Potomac run, there is much less stripping, and because the- 



