I have been immersing myself in our new fountain of knowledge and finding gems all over the place (mangled metaphor is me). Here's what she has to say on Giants that throw stones.
http://lochearnhead.wikidot.com/chapter9
Giants and their Mother.
With the giants of prehistoric Scotland we move into a more tangible field of enquiry, for they lived in identifiable places. Typical are the four brothers of prodigious size who once lived on the west coast of Lewis. They dominated the whole island and kept the men of Lewis under subjection. Their names were Kuoch Mac Nuaran or Nuagaran (Cuithuich Mac Nuadharan) who lived at Dun Chuithaich on a small island at the Sands of Uig, Glom Mac Nuaran who lived at Ballyglom, in Great Berneray, Tidd Mac Nuaran who lived at Tidberry, also in Great Bernera, and Dearge Mac Nuaran who occupied the broch at Carloway. As we might expect, their names derive from beacon signals and hunting. G. cuithe can mean ‘trench, pit (deer trap)’, G. glom may be ‘rocky cleft (deer trap)’. G. dùd is ‘blast of a horn (signal)’, a beacon or signal word also found at Duddingston, Midlothian, below Arthur’s Seat, and in Sc. dod attached to certain hills in the south of Scotland, and G. dearg is ‘kindle, burn’. These four giants were personifications of the signal beacons which once controlled the rhythm of life in Lewis. In fact they all lived very close to one another and may be regarded as four manifestations of a single beacon, no doubt known as Nuadharan. (cf G. nuaudhulig ‘all-heal’, the mistletoe)
Giants were also widespread in Lowland Scotland where they lived in very visible sites such as hill forts or watch hills which afforded a wide view of the surrounding country. The giant of the Eildon hills was known as Wallace. The giant of Norman’s Law in Fife was known as the Devil (G. diabhol can be interpreted to mean ‘god of fire’, or ‘fire giant’). The stone that he flung when fighting with the giant of Law Hill, Dundee, was known as the ‘Deil Stane’. The giant of Ben Ledi, reputed to be the strongest, or most visible, of his kind in Scotland, was called Samson, and his putting stone was pointed out to visitors to Callander. One of the three giants in Inverness was known as Patrick, perhaps representing the same obscure word as Puderach, the standing stone in Balquhidder. The Red Etin had three heads which may represent beacons on Castle Hill, Arthur’s Seat and Calton Hill in Edinburgh. It has been suggested that the name ‘Arthur’ arrived there after Arthurian romances became popular at the Scottish court, D.A. Mackenzie 1935, 117. but Arthur may have been there first for he ‘controlled the armies of Britain’ and was himself a major hunting beacon. The male giants who divided up the Lowlands between them were preceded by a single female beacon. D.A. Mackenzie 1935, 139-40.
The story of giants or the devil or witches hurling stones great distances is widespread. Is this perhaps a misinterpretation of a phrase which meant, instead, that a beacon signal travelled a great distance? It might in that case have evolved out of the link between G. clach ‘stone’ and E. clock, clack, clap, and clapper. Du. klok ‘bell’ is also relevant. G. clachan ‘testicles’ are in evidence in Romanesque decoration. This reflects the fact that the ringing of bells replaced beacon signals. Ossian the deer-hunter complained that the bells of the priests disturbed him – in other words, the feudal calendar was at odds with the native calendar. However the etymological links suggest that the original bell or clock consisted of two stones knocked together to make a ringing noise. Cup and ring marks were made by repeatedly knocking a stone hammer on a fixed slab. Would this make a ringing noise on a frosty winter’s night? A field experiment appears to be call for here.
Wonderful stuff.