CONFIRMATION AFFORDED BY THE SUN STONE. 
And now we have to compare the result of our work upon the 
stars with the angle for sunrise on the longest day shown by the 
Hele stone. I find that this angle was 41°, 7’ 16”, or there- 
abouts. The method by which this angle can be obtained must 
be explained. As Dr. Petrie has proved, and as anyone can 
prove for himself on the spot, the only place whence any proper 
observation of this event can be taken is from the back of, and 
between the uprights of, the great trilithon, because only from 
that place can the peak of the Hele stone be seen just level with 
the horizon beyond the valley ; and the moment of sunrise is that. 
at which his topmost limb first glances above the horizon. The 
date by sunrise at the longest day may be got at if we find the 
alignment along which the builders looked. For the angle from 
the East made by this alignment would depend on the position of 
the plane-of the Ecliptic, and this has been decreasing ever since 
Stonehenge was built. The deviation of the plane of the Ecliptic 
proceeds at the rate of about 47-6 in a century. This is a much 
smaller matter than we found when we looked to the precession 
of the stars ; and when one comtemplates the rocks that go to 
make Stonehenge, one might fear that no certain evidence could 
be obtained with regard to so delicate an affair from witnesses so- 
rough and rude. But the builders of Stonehenge knew what 
they were about, and, just as in the instance of the outlying stones 
they gave themselves and us an intervening piquet of direction, 
so here they did the same. ‘This intervening piquet is afforded 
by what is called the Slaughter stone. This is a huge mass some 
30 feet long, lying prostrate on the ground, well nigh immovable. 
At its end nearest the Hele stone, you can see a line of small 
picked marks, which look just as if they were the first steps in 
the process necessary for the breaking off of a somewhat un- 
shapely lump of rock that juts out there towardsthe South. And 
Dr. Petrie even ventured to think that these pick marks shewed 
