Summer blot – first possible day. Line 52-54
On the summer blot the shadow cast by the higher stone moves across the lower stone, which stands 2.2m away so that the shadow reaches precisely up to top of the lower stone. The higher stone is leaning 9° and its straightened up position is calculated. The positions of the stones after this adjustment were used to calculate the sun line.
The animation shows the shadow’s passage the day before, and exactly on the first possible day of the summer blot:
The gradient of the top of the stones are in good alignment with the sun’s path.
The passage of the shadow is correct the day of the summer blot. That day only just a very thin streak is sunlit above the shadow on the lower stone.
Since the higher stone today is leaning, one can today see how the shadow falls first 14-15 days late, around July 22-23.