The crossing of the strata shows that the tracks are the work of human hands, if indeed it were not preposterous to think of anything else in rocks of that period. Still the tracks are so well made that one is tempted to ask if they can be real. They alternate right and left, though the erosion and travel have worn out some of the left tracks. A wagon road passes over the rock and was the cause of the present exposure of the stone. It can be readily found a fourth of a mile or less from the Pine Grove schoolhouse.
A number of inscribed rocks have been found in Maine and information of others has been obtained. The most interesting of them and the largest group series yet discovered in New England is shown in Pl. XII.
[Illustration: BUREAU OF ETHNOLOGY TENTH ANNUAL REPORT PL. XII
The rock upon which the glyphs appear is in the town of Machiasport, Maine, at Clarks point, on the northwestern side of Machias bay, 2 miles below the mouth of Machias river. The rock or ledge is about 50 feet long from east to west and about fifteen feet in width, nearly horizontal for two-thirds its length, from the bank or western end at high water, thence inclining at an angle of 15° to low-water mark. Its southern face is inclined about 40°. The formation is schistose slate, having a transverse vein of trap dike extending nearly across its section. Nearly the entire ledge is of blue-black color, very dense and hard except at the upper or western end, where the periodical formation of ice has scaled off thin layers of surface and destroyed many figures which are remembered by persons now living. The ebb and flow of tides, the abrasion of moving beach stones or pebble wash and of ice-worn bowlders, have also effaced many figures along the southern side, until now but one or two indentations are discernible. Visitors, in seeking to remove some portion of the rock as a curiosity or in striving to perpetuate their initials, have obscured several of the most interesting, and until recently the best defined figures. It was also evident to the present writer, who carefully examined the rock in 1888, that it lay much deeper in the water than once had been the case. At the lowest tides there were markings seen still lower, which could not readily have been made if that part of the surface had not been continuously exposed. The depression of a rock of such great size, which was so gradual that it had not been observed by the inhabitants of the neighboring settlement, is an evidence of the antiquity of the peckings.