owned by John Glass, south side by Sebastian Dean. Distance from the initial is 18.65 miles and 310.51 feet north of the tangent. The last mound marks the junction with Maryland. It is mile east of the stone above described. The new monument was placed in centre and is 19.45 miles distant and 333.53 feet north of the tangent. Abraham Thomas owns the land on the south side. This monument is 16 inches square-dressed 34 feet and rough cut 3 feet. The underground cube is 16x16x16 inches. As was indicated by the last three mounds on the third tangent in 1883, the line tends to come back towards the theoretic curve through the S. W. corner of Pennsylvania. The stone pile one mile east of the summit of the Laurel Hills is 3.6 miles distant and 25.6 feet north of the tangent through the first mound. It should have been theoretically 7.1 feet north, showing thus a bend to the north of 18.5 feet, a very rapid gain. The eighth mound at a distance of 10.8 miles has an offset of 119.5 feet, theory makes it 64.7 feet, the bend north is therefore 54.8 feet. At the stone marking the north end of the meridian through the Fairfax stone, the offset is 306.5 feet; it should have been by theory 193.0 feet, showing a bend to the north of 113.5 feet. At the junction with Maryland, 19.45 miles distant, the offset is 329.5 feet north of the tangent through the first mound; it should have been theoretically 208.5 feet, showing an accumulation of bend to the north of 121.0 feet. (See Table at the end.) The initial mound of the fourth tangent is 172.1 ft. south of the theoretic curve through the S. W. corner of Penn., and the bend north at the end of the line amounts to 121.0 ft. so that the line at its termination is only 51.1 feet south of the theoretic curve. Taking the line section by section, it will be seen that the apparently regular part is very irregular, that is, when referred to the astronomical parallel, and that the irregular portions are about as well laid down as the other. The first section between the S. W. corner, latitude 39° 43′ 18′′19, and Lantz's Hill, latitude 39° 43' 18'97. By reference to the theoretic curve through the S. W. corner, the old post-hole on Lantz's Hill falls 11.75 feet south; astronomically it is 78.93 feet north, or the line in 11.5 miles is in error 90.68 feet. If the astronomical parallel should be insisted upon, the line would have to be made very irregular instead of the almost theoretic curve now existing. The next section, Lantz's Hill, latitude 39° 43′ 18′′97, and Bald Hill, latitude 39° 43' 18'44, (the latitude station is 1 miles west, but the latitude here is assumed to be the same.) The old mound on Bald Hill is about 54 feet south of the point on Lantz's Hill astronomically. It is 69.7 south of the theoretic curve through Lantz's Hill, or in 14 miles the line is in error only about 15.7 feet. This theoretically irreg ular portion is thus seen to be astronomically quite regular. The next section, Bald Hill, latitude 39° 43′ 18′′44, and Harvey's, latitude 39° 43' 18"14. Astronomically, Harvey's is a little over 30 feet south of Bald Hill; referred to the theoretic curve through Bald Hill, it is over 85 feet south. The error in ten miles is about 55 feet. The last section, Harvey's, latitude 39° 43′ 18′′14, and the north terminus of the Fairfax stone meridian, 1859, latitude 39° 43′ 17′′92. (Latitude was observed at this stone, and I use this instead of the end of the line mile east.) The latter is 22.26 feet south of the former astronomically; by refer ence to the theoretic curve through Harvey's, it is 113.5 feet north of Harvey's, or an error of 135.8 feet in 18.65 miles. On a uniform spheroid, one with no inequalities in elevation, and no variation in density, it would be a very simple matter to lay down a parallel of latitude, but when we have to deal with a very uneven surface and deviations of the plumb line or displacement of the zenith, the laying down of such a line becomes both difficult and expensive, consequently astronomers adopt practical rather than purely theoretical methods in dealing with boundaries of this nature. All are approximations. A wholesale correction of this boundary would have caused endless litigation, and a large outlay of money, without any practical return to the States. Where the old marks were so numerous as on the last thirty-four miles, there was no occasion for making any change in existing points, and on the first part of the line where the marks were rather scarce, no material change was made in the traditional boundary. Quite a number of the old mounds on that portion run by Mason and Dixon have been identified by the close agreement of the two measurements. It is thus very easy to prove that the stopping place of Mason and Dixon is not the "Second Crossing of Dunkard," but Brown's hill a short distance west of the third Crossing of Dunkard. Besides the agreement of distance between the last seven or eight mounds on the west end of Mason and Dixon's work, an extract from their field notes found in the State Department, Washington, D. C., gives positive evidence of the west terminus being a mound on a high hill. "The sector stood on ye top of a very lofty Ridge, but when ye offset was made of 3 ch., 38 lks., it fell a little Eastward of the top of ye Hill; we therefore extended ye true Parallel 3 chs. 80 links westward, which fell on ye top of said Ridge; there, viz: At 233 miles, 17 chains, 48 links from the Post marked west, in Mr. Bryan's field we set up a Post marked W on ye west side, and heaped round it earth and stone three yards and a half diameter at ye Bottom and five feet High. The figure nearly conical." This post is 230 miles, 18 chains, 21 links from the beginning of the west line. The mound on Brown's Hill was the most westerly one found during the survey of the boundary. There were several places where the mounds (or traditions of mounds) were too close together for mile marks, and I was not able to account for them until Mason and Dixon's notes were consulted. From these I learned that mounds had been placed not only at every mile, but also on the summit of the prominet ridges. It is very evident that many of the mile mounds fell in hollows or on the hill sides and were destroyed in the course of time, and that most of these now in existence are the ridge mounds, and the distance between those of course vary as the hills themselves. These ridge mounds are the principal ones marked with new stone monuments. No attempt was made to restore the mile marks, as the adjacent ridges are intervisible and generally not very far apart. There are two charts of the line, both on a scale of . The first was designed to show the method of tracing the boundary by means of tangents, all the old line marks, the new monuments and the variations of the boundary from a theoretic curve on a uniform spheroid. This theoretic curve is drawn through the S. W. corner of Pennsylvania for convenience; it might just as well have been assumed through any other point, or even made the mean theoretic parallel. The second chart shows the State line in place and is the complete map of the boundary, giving the stones by number, and the distance in miles and feet, counting from the S. W. corner. These two maps are essential for showing all the details of the survey, and are complete in themselves, without reference to the chart of 1883, which is included in the first, with some changes. Yours respectly, C. H. SINCLAIR, Coast & Geodetic Survey. JAMES MCCULLOUGH, W. W. WALKER, Commissioners of Pennsylvania. J. C. GIST, JOHN J. CHIPLEY, F. L. HOGE. Commissioners of West Virginia. N. end of meridian through Fairfax stone, 18 3537.1 306.5 193.0 113.5 Tangent corrected for constant offset. [No. 95 filed in Department of Internal Affairs, July 10, 1886.] Alexander M'Lene, Esquire, was appointed to assist Colonel Andrew Porter in the business of running and marking the western boundary. of this Commonwealth, to the north-west corner thereof. [Colonial Records, Vol. XV, page 19.] Commissioners for Western Boundary Line to Council, 1786. SHANANGOE CREEK, June, 25th 1786. GENTLEMEN:-We beg leave to inform Council, that on the 19th inst. we began to extend the line of the Western boundary of the State, and have proceeded upwards of Three Miles. We have fallen in with several Hunting parties of Indians since our arrival in the woods; they all appear friendly and peaceable. We are, with respect. Gentlemen Your Obed't Serv't, [Pennsylvania Archives, Vol. XI, page 26.] ANDREW PORTER, Commissioners on West Boundary to Council, 1786. WESTERN BOUNDARY OF PENNSYLVANIA, Sept. 3d, 1786. GENTLEMEN:-We beg leave to inform Councils That the Line of the Western boundary of the State is extended from the South West corner One hundred & forty Three Miles and hope to compleat it by the first of next month. We are now on Waters running Northward, but have no information of the distance to the Lake. The Indians appear friendly and have expressed no dissatisfaction to our running the Line. We are with Respect, Gentlemen your obedt. servt. [Pennsylvania Archives, Vol. XI, page 52.] ANDREW PORTER, ALEXANDER MCCLEAN. Report of Commissioners on Western Boundary Line, 1786. We the Commissioners appointed to ascertain and complete the Line of the Western boundary of the State of Pennsylvania, beg leave to Report: That we have ascertained and completed said Line by astronomical observations as far as Lake Erie; having opened a Vista, and planted stones in the proper direction, marked on the east side P. and that said Line extends some distance in the Lake. October 4th, 1786. [Pennsylvania Archives, Vol. XI, page 69.] ANDREW PORTER, Journal of Andrew Porter one of the Boundary Commissioners. May 17th, 1785. Set out on our journey to determine the Western boundary of the State and arrived this evening at Wright's Ferry on the Susquehannah: found the roads extremely bad & much out of repair. The soil fertile abounding with Lime Stone. 34 M. 18th. 19th. Crossed the Susquehannah early this morning-a considerable quantity of rain fell last night and continued raining the fore part of the day-tarried a few hours in Yorktown-arrived this. evening in Abotstown. This place consists of but a few houses, made of logs and frame. The soil in general but little inferior to that of Lancaster County. Dist 27. Miles. Crossed the South Mountain at Black Gap; the roads much out of repair. The land from Abotstown to the mountain is of a slaty kind in genl & without Lime Stone. Arrived this evening at Mr. Crawford's. 30 miles. |