You are willfully ignoring my repeatedly pointing out that the fact that John Michell got a few grid refs wrong does not matter because he did not use them to work out his alignments. The alignment he gives to that boundary stone is at about 66.5 degrees.

Lockyer wrote in the caption to figure 56 on page 283 of Stonehenge and Other British Stone Monuments that the Men an Tol was “an apparatus for observing the sunrise in May and August in one direction and the sunset in February and November in the other. Sun’s declination 16° N or S.” The plan of Men an Tol that he shows is inaccurate because he shows the stones in a more or less straight line which they are not.

I calculated that allowing for the height of the horizon the May Day sunrise would be at an azimuth of about 69.36° - I could have been wrong. The azimuth I calculated was for the point at which the horizon bisected the sun.

So Michells' guesstimate wasn't too bad and is probably correct for the azimuth at which the sun first shows above the horizon. He was right that the boundary stone, that does exist at the grid ref I gave earlier and is shown in the correct location in the map on page 79 of the 1979 edition of TOSOLE, is in the direction of May Day sunrise.

This line from the Men an Tol does not rely solely on it and the boundary stones of course.