'214: Part III. — Eighth Annual Report 
The further protection afforded them by the islands and wash rocks of 
the Sound of Barra, in which they are situated, is also helpful. Traigh 
Mohr, which is the most extensive, is also the best protector. It is 
sheltered from south-easterly gales by the islands of Gighay and Hellisay, 
and by the rocks and islets running westwards from Hellisay to Griana- 
meal. East and north-east winds are broken by the large island of 
Eriskay, by the Stack Islands, and by the wash rocks between the latter 
and the island of Fuday. From all other winds it is completely protected. 
Kilbar Strand is more exposed, especially to south-east winds, but the 
island of Fuday shelters it from the north-east. Traigh Sghuir'aval is the 
least sheltered of all. While Fuday Island protects it on the south-east, 
north to north-easterly seas from South Uist, and along the western side 
of South Uist, are only interrupted by the shallow banks lying at the 
western entrance to the Sound of Barra and to the north of Traigh 
Sghuir'aval. From high-water mark at the time of the greatest springs to 
low-water mark at the same season, the sand banks of Traigh Mohr are 
dry to the extent of almost a mile. Similarly at Traigh Sghuir'aval the 
tide ebbs for about half a mile, while at Kilbar Strand the distance is 
much less. The distance across Traigh Mhor from the Island of Oronsay 
to the rocks on the southern side of Traigh Mhor at low water is three 
quarters of a mile. The extent of sand banks dry at Traigh Mhor at 
lowest tides is about 320 acres, or about the same as is dry at the banks 
at Traigh Sghuir'aval and Kilbar Strand combined. 
The banks of Traigh Mohr and Kilbar Strand are connected by the 
neck of sand which, as the tide recedes, dries between Oronsay and 
Eoligary, but Traigh Sghuir'aval is completely separated off from Kilbar 
Strand by the point of land about opposite Eoligary House. 
Traigh Mohr is bluntly triangular, with the blunted apex pointing 
shore wards, the mark of low water forming the base of the triangle. 
Traigh Sghuir'aval is quadrangular, its long diameter being nearly south- 
south-east and north-north-west, while it is somewhat broader at its 
western shoreward side. It is fully two-thirds of a mile long, and the 
whole sand bank that ebbs dry contains upwards of 200 acres. As 
the geological formation of Barra is Laurentian gneiss, the sand bank, 
which is the product of denudation of gneissose rocks, is composed of 
particles of quartz felspar and mica — the predominating constituents of 
such rocks. 
"While the other two banks yield cockles, these are produced in 
greatest abundance on the beach at Traigh Mhor. But the whole of 
the sandy stretches of Traigh Mhor do not furnish an equal yield. The 
cockles are comparatively few in that part of the bank nearest high 
water, but from a quarter of a mile from high-water mark down to the 
low-water mark of neap tides they increase in numbers and size, and 
between the low-water mark of 1 neaps ' and the low-water mark of 
' springs ' they are most abundant. At the lowest of spring tides they 
occur alongside of a plentiful supply of Solen siliqua, which, like the 
cockles themselves, attain a giant size. I have found the cockle also 
to be abundant in the sand bank which stretches seawards, and is 
for a few hundred yards covered by not more than 2 or 3 feet of 
water at lowest 'springs.' More than 200 acres of Traigh Mohr are 
cockle-bearing, and the crop which this acreage is capable of producing 
is enormous. This extent may be considered as rich in cockles, and 
far surpasses anything that either of the other two baylets can show. 
So what is said has special reference to Traigh Mhor unless when other- 
wise mentioned. Having regard to the immense quantities of cockles 
