"The Great Circle of Stennes, or Ring of Brogar, is a deeply entrenched circular space containing almost two acres and a half of superficies, of which the diameter is 366 feet. Around the circumference of the area, but about thirteen feet within the trench, are the erect stones, standing at an average distance of eighteen feet apart. They are totally unhewn, and vary considerably in form and size. The highest stone was found to be 13-9 feet above the surface, and judging from some others which have fallen, it is sunk about eighteen inches in the ground. The smallest stone is less than six feet, but the average height is from eight to ten. The breadth varies from 2-6 to 7-9 feet, but the average may be stated at about 5 feet, and the thickness about 1 foot--all of the old red sandstone formation. The trench round the area is in good preservation. The edge of the bank is still sharply defined, as well as the two foot-banks or entrances, which are placed exactly opposite to each other. They have no relation to the true or magnetic meridian, but are parallel to the general direction of the neck of land on which the circle is placed. The trench is 29 feet in breadth, and about 6 in depth, and the entrances are formed by narrow earth-banks across the fosse. The surface of the enclosed area has an average inclination to the eastward. It is highest on the north-west quarter, and the extreme difference of level is estimated to be from 6 to 7 feet. The trench has the same inclination, and therefore could never be designed to hold water." THE EXCAVATION OF MAES-HOWE. On Monday the 8th of July, a number of men under the superintendance of Alexander Johnson, Mr. Wilson's foreman--a most active and intelligent fellow--proceeded with the work that had been commenced on the previous Saturday, and before evening discovered a passage on the west side, which afterwards proved to be the entrance into the interior of the tumulus. This passage was covered over with large flag-stones, one of which having been with some difficulty upraised, we effected an entrance, but found a considerable accumulation of earth and stones, which was removed on the following day, and Mr. Wilson, after careful examination, in which his engineering experience was of the highest importance, agreed to my suggestion that the excavation should be proceeded with from the centre of the hillock. I am chiefly indebted to my friend Mr. George Petrie for the following measurements, which I believe will be found to be substantially correct:--