Chapter VII, the result is as follows. The Barnhouse-Maeshowe line was

established about 700 B.C., when the obliquity had a value of 23° 48′ according to Stockwell’s tables. (Fig. 40.)

I confess the late date does not surprise me. The masonry of Maeshowe differs widely from that of other similar structures in that the sides of the gallery and chamber, instead of being composed of upright stones, are built in regular courses.

I do not believe that the Maeshowe structure was built to observe a winter sunrise twenty days from the solstice, nor can I think it was set up at midsummer by someone who had only dealt with a high sun and a sea horizon, and imagined that the sunrise and sunset points were exactly opposite to each other. It was a priest’s house, and the alignment of the passage to the Barnstone was for the exchange of signals, probably by lights in Maeshowe itself.

The Ordnance maps give no indication of stones, &c., by which the direction of the midsummer setting or the midwinter rising and setting might have been indicated from either the Maeshowe or the Barnstone.

To sum up the solar alignments from the circle.

We have the May sunrise marked by the top of Burrien Hill, from 600 to 700 feet high, Az. 59° 30′.

We have the November sunset marked by a standing stone on the other side of the Loch of Stenness, Az. 53° 30′.

June rising, Line from Barnstone over Maeshowe tumulus.

December rising, tumulus (Az. 41°) on Ward Hill.

December setting, tumulus Onston 36° 30′.

It is not a little remarkable that the summer solstice rising and the winter solstice rising and setting seem to have been provided for at the Stenness circle by alignment on the centres of tumuli, two of them, across the Loch, one the Onston tumulus to the S.W. (Az. 36° 30′), the other tumulus being on Ward Hill to the S.E., Az. 41° (rough measurement).

If the Maeshowe tumulus was a structure erected at the time I have suggested to use the Barnstone for the summer solstice rising; then these two other tumuli, to deal with the winter solstice at Stenness circle, may have been built at the same time. All these provided for a new cult.

There are also tumuli near the line (which cannot be exactly determined because the heights of the hills are unknown) of the summer solstice setting; none was required for the sunrise at this date, as the line passes over the highest point of Hindera fiold, a natural tumulus more than 500 feet high, and on that account a triangulation station.

Another argument in favour of the tumuli being additions to the original design is that the place of the _November_ setting from the Stenness circle is marked, _not_ by a tumulus, but by a standing stone. As this stone, near Deepdale, and the tumulus at Onston are only about 1200 yards apart, the suggestion may be made that under certain unknown conditions and possibly in later times tumuli in some cases replaced stones as collimation marks.

With regard to the clock-star, it is to be feared that the stones in the N.E. quadrant as viewed from the circle which might have given us a clue have been removed. As the latitude of Stenness is N. 59°, some star with a less declination than N. 31° would have been chosen, assuming that the sky-line towards the N. point is not very high.

[20] See especially _Nature_, July 2, 1891, p. 201.

[21] Gardner: Paisley and London.