a man, joined together, and covered with grass and weeds. Out of
the top of one of them a column of smoke slowly rose, and at its
base there was a hole about three feet high and two feet wide,
which seemed to lead into the interior of the hillock--its
hollowness, and the possibility of its having a human creature
within it being thus suggested. There was no one, however, actually
within the _bo'h_, the three girls, when we came in sight, being
seated on a knoll by the burn-side, but it was really in the inside
of these two green hillocks that they slept, and cooked their food,
and carried on their work, and--dwelt, in short."[58]

These two "green hillocks," and other structures of the same nature, are
shown in the accompanying diagrams[59] (Plates I.-XVI.), which explain
their formation better than any written description. It is enough here
to state that they are built of rough stone, without any mortar. "Though
the stone walls are very thick," says my authority (p. 62), "they are
covered on the outside with turf, which soon becomes grassy like the
land round about, and thus secures perfect wind and water tightness."
Sometimes they occur in groups, as those shown in Plate III.; of which
scene Captain Thomas justly remarks that "at first sight it may be taken
for a picture of a Hottentot village rather than a hamlet in the British
Isles."[60] Here there is little or no grassy covering outside, however;
and consequently none of the hillock-like effect. But this is very well
shown in Plates VI. and VIII. Of the "agglomeration of beehives"
pictured in the latter, Sir Arthur Mitchell observes:--"It has several
entrances, and would accommodate many families, who might be spoken of
as living in one mound, rather than under one roof" (_op. cit._ pp.
64-5). Of another such dwelling, now ruined, he says that it could have
accommodated "from forty to fifty people."