one on each of its closed sides. The roof is formed by corbelling the
walls and finishing off with slabs laid across. If one sits within the
chamber and looks in a direct line along the passage one sees the
Barnstone.

A series of measurements and alignments have been taken to connect the
Maeshowe tumulus with the Ring of Brogar. Thus we have already seen that
the distance from the Barnstone to the Watchstone is the same as from
the Barnstone to the tumulus. Moreover, the Watchstone is equidistant
from the ring and from the tumulus. Again, a line from the Barnstone to
the tumulus passes through the point of the midsummer sunrise and also,
on the other horizon, through the point of the setting sun ten days
before the winter solstice; the line from the Watchstone to the Brogar
Ring marks the setting of the sun at the Beltane festival in May and its
rising ten days before the winter solstice, while the line from Maeshowe
to the Watchstone is in the line of the equinoctial rising and setting.
These alignments are the work of Mr. Magnus Spence; readers must choose
what importance they will assign to them.

The Inverness type of circle is entirely different from that of which we
have been speaking. The finest examples were at Clava, seven miles from
Inverness, where fifty years ago there were eight still in existence.
One of these is still partly preserved. It consists of a circle 100 feet
in diameter consisting of twelve stones. Within this is a cairn of
stones with a circular retaining wall of stone blocks 2 or 3 feet high.
The cairn originally covered a circular stone chamber 12-1/2 feet in
diameter entered by a straight passage on its south-west side. In other
words, the Inverness monuments are simply chamber-tombs covered with a
cairn and surrounded by a circle.