DECEMBER 13, 1906] NATURE 151 
abet Tiue Azimuths wae In S. England, as stated in ‘ Stonehenge,” the avail-- 
: able clock-stars were Arcturus and Capella. But 
With sea horizen 1 41 ORE aa SE 44°46 E. | this was for lat. N. 50°. How.about lat. N. 57°? 
»» J elevation ... 43 40 2 10 I find that for this latitude these two stars were the 
ieee y Aya e 46 16 39 30 only ones available for part of the time, and, further, 
se Pon tm coe ees 48 20 36 46 that Castor might have been used at another time. 
» 4 Eye | fowls 50 2 ss Sed 33) 59 In the district round Aberdeen, and especially to: 
These values apply ina general way toboth Sunhoney the westward, the height of the horizon varies greatly. 
and Midmar. The difference of azimuth observed arises | How this affects the star question, and how it is 
from the fact that there is, rous ghly, a difference of needful for archeologists to tale account of it, will 
2° in the angular height of fie horizon at the two 
places. - I attach greater weight to the measures at 
Midmar, as the direction was taken to a stone on the 
other side of the circle. It may be that this way of 
making the direction line ‘‘siccer’’? was generally 
taken; the plans suggest but do not prove it. 
Let us, then, look at the Midmar result a little more 
closely. My rough measures gave an azimuth of 
N. 42° E. According to the above table the azimuth 
of the solstitial sunrise to-day, with hills 1° 30! high, 
is practically N. 45° E. There is a difference of 3 
Now in your latitude at the solstice, the sun when 
it rises or sets grazes the horizon for a long time; the 
direction of its apparent motion is only slightly 
inclined to the horizon. To-day it is about 27°. A 
change in the sun’s declination due to the change in 
| hills 2° 30’ high, 
be gathered from the accompanying diagram, which 
Mr. Rolston has been good enough to prepare. 
To show the use to be made of it, let us take the 
observed azimuth at Auchquhorties, N. 19° E. With 
we find that if a star were really 
it must at the time of circle-building have 
°. This was Capella’s 
in question, 
had a north declination of 
Ione 
declination about B.c. 1640, and Arcturus’s about 
B.C. 600. 
There is a difference of a thousand years, and if 
further inquiries show that either or both of these stars- 
may have been used in connection with these circles, 
some progress will surely have been made which it 
seems cannot be made without it. 
It will be clear that when final observations have 
been made at Midmar and other circles which may 
FG. 2.—The recumbent stone and its supporters at Auchquhorties. 
the obliquity of the ecliptic, which was greater in past 
times, will therefore produce a great change in the 
azimuth of sunrise. Thus to give figures ready to 
my hand, if instead of the present declination of 
23° 27! we talxe 23° so’, the declination at B.c. 1000, 
according to Stockwell’s calculations, the present azi- 
muth of N. oy 58’ E. (with hills 1° 30’ high) becomes 
N. 43° 57 E { 
Now this is a degree nearer my value of the azi- 
muth; and if that value is not very much out, and if 
the recumbent stone was arranged in relation to the 
solstice, it is clear that the Midmar stones were set 
up more than 3000 years ago. 
To carry this inquiry further, observations much more 
complete than mine, including observations of the 
sun with accurate time to get the astronomical bearing 
directly, are required. We want, too, observations in 
winter when the leaves are off the trees, so that the 
height of the horizon can be accurately measured. 
To such observations in your high latitude I attach 
very great importance, since changes in direction due 
to the change of obliquity of the ‘ecliptic can be con- 
sidered under much more favourable conditions than 
in S. England in the case of circles connected with 
the sun at a solstice. 
I pass to the azimuth N. 
NO. 1937, VOL. 75 
19° E. at Auchquhorties. 
Photo. by Lady 
Lockyer. 
View from the back looking across the circle. 
be connected with a solstice, the sun and star dates 
may be compared, and each may throw light on the 
other. For instance, if the final values for Midmar 
come anywhere near my provisional ones, we shall 
have an argument in favour of Capella as against 
Arcturus at Auchquhorties, for it is fair to assume: 
that the circles in any one region, whether solar or 
stellar, were started at about the same time; at least, 
the evidence furnished by the Cornish monuments is 
in this direction. 
The result of such detailed inquiries as these wilf 
do much to enable us to form an opinion touching 
the possibility of astronomical considérations having 
been taken into account by the builders of the monu- 
ments. 
I wish to plead for the examination of these circles. 
in the widest possible sense. As I have said, they may 
have served several purposes, some of them at present 
undreamt of, and in this connection I protest against 
the logic of those who hold that because graves have 
been found in them they were constructed wholly for 
purposes of burial, and that no other considerations 
were in the minds of those who set up the stones. It 
is the same thing as to say that because graves are 
found in our churches, the churches themselves were 
not built for the worship of God. 
