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Proceedings of the Royal Society 
(10.) Loch Maddy , a sea loch on the east side of North Uist. A 
walk for about a mile among the hills, during an hour that the 
steamboat was discharging cargo, showed that the rocks had 
their smoothest sides towards the N.W., and their rough sides 
towards the S.E. Boulders in great numbers were lying on these 
smoothed surfaces, and on the N.W. sides of the hills. 
Before concluding his notice of Uist, the Convener may advert 
to one feature in the physical aspect of the island, viz., the ex- 
traordinary number of small lakes. When any of the hills are 
climbed, which afford even a tolerable view of the low grounds, it 
would almost seem that more of the island consists of lakes than of 
dry land. The cause of this feature probably is, that the general 
level of the island is so little above the sea, that the hollows 
occupied by these lakes can never he emptied. It is another 
striking feature, that most of these hollows lie in the same direction, 
viz., W.N.W. and E.S.E. 
VII. — ISLAND OF CANNA. 
The Convener when in the steamboat made the acquaintance 
of Mr William Bain, generally residing at Tiree, who takes con- 
tracts for erecting buildings in the Hebrides. He mentioned 
that he had lately built a new schoolhouse in Canna, an island 
situated near Bum. He told the Convener that he had found on 
the islet of Sanda, which forms the south side of Canna Harbour, 
blocks of a red sandstone which he made use of for the lintels 
and corners of the school doors and windows. The largest of these 
blocks was about 6x4x2 feet. He knew that these sandstone 
blocks differed from the rock of the island, which he described as 
a sort of blue slaty schist, ill-adapted for building. He recog- 
nised these red sandstone blocks as of the same nature as rocks in 
the island of Bum, which were good for building purposes, as he had 
quarried them for that purpose. 
This statement by Mr Bain is confirmed by Macculloch. He 
says — “ Sandy isle, like Canna, presents examples of a circum- 
stance rare in the Western Islands, viz., loose fragments of a 
different rock from that of which it is formed, lying on the surface. 
There are large blocks of red sandstone somewhat rounded, and they 
are found in considerable abundance on the flat shores of both. ‘ The 
