The megalithic mound

The passage

A lot of measurements have been done to check the maps provided within the booklet of Ashmore, P. (1995, page 6).

It looks like that the overview and the crosscut (both derived from Crown Copyright:RCAHMS material) are accurate enough. More precise measurements of important points in the passage can be seen in the below table (where the cross point between C-D and the line M is taken as the origin of the grid, point 0):
Point X Y Z
[cm] [cm] [cm]
C 0 -15+/-1.5 -29+/-0.7
D 0 56.5+/-0.3 91.5+/-0.7
S 179.5+/-0.2 -0.4+/-0.2 0
T 179.5+/-0.2 69.8+/-0.3 0
W' 179.5+/-0.2 -1.2+/-0.1 46+/-0.7
T' 179.5+/-0.2 -1.2+/-0.1 91.5+/-0.7
E 391.5+/-0.3 0 0
G1 948.5+/-0.7 0 0
H1 948.5+/-0.7 72+/-0.7 0
G2 1013.5+/-0.8 -7.2+/-0.1 0
H2 1013.5+/-0.8 68.8+/-0.3 0
U 1579.5+/-1 0 0
I 1579.5+/-1 -32.5+/-0.3 0
K 1579.5+/-1 53+/-0.3 0
J 1579.5+/-1 117+/-0.3 0
These can thus be used to make a model.
Three lines are important in the overview:

The azimuths are determined by: The above azimuths are also caused by a bend in the passage. Such a bend in the passage can also been seen at Wideford Hill.
In Ashmore, P, 1995 the azimuth of line B is: 217o (error unknown).

These lines can also be seen on a picture of the horizon (for a panorama pictures, click here). The altitude of the horizon at the line A is 1o20' +/- 5'.

The Barnhouse stone is enhanced in the above mentioned picture by white contours. The azimuth of this stone is around 221o 5' +/- 15' and its altitude around -0°11' +/- 5' on a distance of 800 [m].

The four blocking stones

There are four blocking stones within Maeshowe.
Below first the dimensions of the entrances (starting from the down-horizontal side and then CCW): The four blocking stones for these entrances/recesses are: The white squares are 100 x 100 [cm]. The yellow lines give the approximate contours of the recess entrance that is (now) closest to the stone.
Remember: the orientation of the stones could be different in the past of course then pictured now!

Passage entrance and its blocking stone

From Davidson and Henschall (1989) can be read that the environment of the entrance blocking stone was different in 1861 than now.

It seems that it was rebuild with a higher roof. According to Gibb, the height of the passage was then 70 cm, if the floor was raised or not, is not really known. I assume that the door-check, which is 88 cm in height, was the original height of the entrance passage. This results in a height of the entrance (W') of 46 [cm] with regard to the reference grid.

The top of blocking stone is at 46 [cm] in the reference grid (S').
(This will have to be verified by means of a mock-up. At this moment it looks like that the left side of the blocking stone [at the present location] is at the same height as the right side of the door check, but on the left side of the blocking stone  is some 5 [cm] lower, so still a possibility of a gap).

An animated picture of ideas around the passage blocking stone is made (see below). These pictures has been derived from plans of the mentioned author in the picture. The height of the inner passage has been equaliized over all maps. The height of the passage blocking stone (in red) has been drawn as mentioned in their papers (sometimes this does not match the real height of the blocking stone).

Relation between recesses

From the general overview picture one could deduct that the lines MKL and KO are straight lines. But if one does measurements inside the building it looks a little bit different. No effort is putten in making a new overview (because one should need much more information), but some lines are measured. The line identification can be found in the below picture:

The following has been measured:

Light path within Maeshowe

At winter solstice the sun shines within the passage and chamber. At present, the sun beam is getting in at winter solstice day, to the left and down of the center recess (CC). See also the picture, which has been made around winter solstice.
A calculation model of Maeshowe has been made, using the measurements mentioned on this and other page. This model has been used to calculate the below simulated light patches in 1996 CE and 2800 BCE.

Simulated light patch at 1996 CE

In the below table one sees how long the sun will shine in the chamber on the back wall at 1996 CE on the days before/after winter solstice (220o 55' on December 21, 1996):
1st light
2nd light

Remark: This is calculated as the passage is now (so with higher passage roof and no blocking stone) (photo's made from the back wall of the chamber towards the outside).
Based on my ideas, the custodians of Maeshowe watched the sunsettings in 1996 en 1997. At last the reappearing of the sun behind Ward Hill has been seen by the custodians of Maeshowe on Dec. 2nd, 1997. Videos and pictures have been made in Dec. 1998.
The reappearing of the sun light at 20 days before/after winter solstice and from 48 to 11 minutes before sunset is simulated with an animated picture (2 pictures per minute). The size and location of several corners of this animated picture related to the referance grid are:
corner location
left down 1579,5 130 0
right down 1579,5 -50 0
right up 1579,5 -50 80
left up 1579,5 130 80

Simulated light patch at 2800 BCE

In the below table one sees how long the sun will shine in the chamber on the back wall at 2800 BCE on the days before/after winter solstice (219o 20' on January 13, -2799):
1st light 2nd light
Day first last first last
before/after minute minute minute minute
before before before before
solstice sunset sunset sunset sunset
0 21 18
5 22 18
10 26 17
15 32 20
20 41 24
22 45 24
23 47 24 13 11
24 49 22 18 11
25 51 13
30 54 23
Remark: Around 23 days before and after winter solstice sunset the sun reappears in the same fashion as now a days. Remember this 22/23 days could be an important period, because this was in (pre?)historic times a month.

In the following picture one can see the moments the sun is on the back wall around winter solstice (when no passage blocking stone is in place: the yellow gives an idea when the sun shines through the present entrance or the entrance of Petrie/Burl, the red shaded part gives an idea when the sun will shine on the back wall if the height of the entrance is as presented by Gibb/Reijs):


Looking at the data found on this page, it seems that Maeshowe had not one but two alignments! One alignment at winter solstice sunset and one a (pre?)historic month (22/23 days) earlier. If both of the aligments were really used (perhaps only the 23 days alignment could have been used), is difficult to determined (yet).

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Major content related changes: |Dec. 22, 1999