I pass now from barrows to stones. There is one about which there can be no question. It is a famous Cross, a “Longstone” at which all travellers stop on their way from St. Cleer to the Hurlers. It occupies nearly the same position on the S.W. horizon as does the long tumulus on Caradon Hill in the S.E. quadrant. From the _South_ Circle, and this is important, its Azimuth, S. 64° W., is nearly the same; it marked, and still marks, the sunset point on the critical days of the May year in November and February. There is another stone marked on the Ordnance Map Az. N. 88° E. from the N. circle. It has been removed, so I may fairly assume that it was really an ancient stone. Captain Henderson’s value for the height of the horizon is 11′ 31″. The table on p. 117 will show that in this direction we have to deal with Betelgeuse as a warner for the summer solstice. The resulting date is 1730 B.C. It would appear that possibly this is not the only stone dealing with (later) solstitial alignments. Lukis gives two stones on the west side of the circles which on the Ordnance Map are classed as boundary stones: they lie on a boundary beyond all question, but also beyond all question they are as ancient as the stones of the circles themselves. From the N. circle they are almost but not quite in a line, and the azimuth of the south stone is S. 49° W. This is a solstitial azimuth. I think, therefore, that we may accept this as another evidence of the worship of the setting sun at the winter solstice, _from the N. circle_, and in this we have still further evidence that to the worship of the May year in the south circle was added later one dealing with the solstitial year which was chiefly carried on in the N. circle. CHAPTER XV THE DARTMOOR AVENUES In Chapter XI. I referred to the very numerous alignments of stones in Brittany, and I was allowed by Lieutenant Devoir, of the French Navy, to give some of his theodolite observations of the directions along which the stones had been set up. The conclusion was that we were really dealing with monuments connected with the worship of the sun of the May year, a year which the recent evidence has shown to have been the first used after the length of the year had been determined; thus replacing the lunar unit of time which was in vogue previously, and the use of which is brought home to us by the reputed ages of Methuselah and other biblical personages, who knew no other measurer of time than the moon. There was also evidence to the effect that in later times solstitial alignments had been added, so that the idea that we were dealing with astronomically oriented rows of stones was greatly strengthened, not to say established.