At the top of the hill, about 660 feet above the sea, several boulders were found, the largest being 4 x 3 x 3 feet. These boulders were resting on a bed of sandy clay, and on a slope of the hill facing west by south. The west side of the boulders was well rounded, as if ground down and smoothed by the friction of bodies passing over it from the west.

All the rocks exposed on the hills here, up to the summit level of the road, which reached about 927 feet above the sea, showed smoothings on their west sides.

The whole of Glen Urquhart has evidently, at some former period, been choked with drift. Beds of gravel, clay, and sand still remain on the hills on each side up to the very top. Hence, probably, the luxuriance of vegetation which this beautiful glen manifests.

On the north bank of Loch Ness, about half a mile to the east of Urquhart, a number of conglomerate boulders lie on the hill side. In walking up the hill the Convener counted six, of which the largest was 7 x 5 x 4 feet, from a level of 200 feet to a level of 800 feet above Loch Ness.

The rocks of the hill here are gneiss, so that these boulders have been brought to where they now lie, most probably from Mealfourvounie, which consists entirely of conglomerate rock, and is situated a few miles to the west.

One of the boulders is at a height of 340 feet above Loch Ness, which corresponds with the line of an old horizontal terrace, visible along the south bank of Loch Ness to the eastward.

At the height of 450 feet above the loch, deep beds of a fine sandy clay occur, just above the landing pier at Urquhart.

XVII.-FORT AUGUSTUS.

On the Corryarrick road (about two miles S. W. of the town) one boulder was noticed which seemed to indicate the direction in which it had come. Fig. 46 shows this boulder of grey gneiss lying on a steep bank of gravel at the base of a rocky cliff, which is a buffcoloured felspathic rock. The slope of the hill is towards N.W. The boulder, therefore, probably came from that direction. It happens to be at the same height above Loch Ness (viz., 207 feet) as the lowest of the conglomerate boulders above mentioned seen to the east of Urquhart.

XVIII.-BEN NEVIS.

The track commonly followed by tourists ascending the mountain leads up the N. W. shoulder of the hill. Boulders of enormous size occur on each side of the track. The following measurements will give some idea of the size of these masses; they happened to be within from 20 to 30 yards of the track; but larger boulders were seen at a greater distance: A boulder 16 x 10 x 10 feet, partially sunk in a gravel bed; a boulder 15 x 7 x 5 feet, lying on rock; a boulder 13 x 7 x 4 feet; a boulder nearly cubical, the sides being about 4 feet square. The three first mentioned had their longer axis N.W. and S.E.; and this was the rule with almost all the boulders, whose length was much greater than their breadth. The boulders measured were at levels above the sea between 900 and 1200 feet. But there were boulders of great size up to 2000 feet or more, and there were some near the base of the mountain. Many of these last-named had, however, been utilised for building purposes. Mr Doig, builder in Fort-William, who accompanied the Convener in his ascent, mentioned, that having been contractor for the Town Hospital, he had made use of one boulder, situated at the foot of the hill, which was four times as large as any of those above mentioned, and that all the rubble-work of the front wall of the hospital-extending to about 80 yards-had been obtained out of this boulder.

Mr Doig, who evidently was intimately acquainted with both boulders and rocks on Ben Nevis, had no doubt that all the boulders on the N.W. shoulder of the Ben were different from any rock in the mountain. He stated that the boulders were mostly all granite, both red and grey granite, but mostly grey. Those examined by the Convener were all grey granite, very similar to the rock worked at Ballachulish and Duror, about 30 miles to the west.

XIX. SKYE.

The Convener regrets not having had an opportunity of visiting Skye, except at one spot on the west coast, viz., Loch Scavaig, where the steamer stops for an hour to allow tourists to visit Coruisk. Macculloch's book, published in 1818, and the paper which the late

Dr

Principal Forbes read in this Society on the Cuchullin hills (“ Edin.

VOL X.

U

New Phil. Journal" for 1846) show that in different parts of the island there are boulders and smoothed rocks well deserving of careful study.

After what Principal Forbes said about the existence of smoothed rocks, and of grooves or striæ on these rocks (which he unhesitatingly ascribed to glacier action), it is impossible to dispute that on this island, small as it is, there must have been ice enough in the different corries to form glaciers. Perhaps there would be less difficulty in adopting the theory, were it supposed that Skye had stood much higher out of the sea at the time when these effects were produced.

Principal Forbes in his paper, among other effects ascribed by him to the Skye glaciers, speaks of "the occurrence of large angular detached masses of hypersthene rock poised upon others, or fantastically balanced on the insulated tops of the elliptical domes of rock” (page 92). He also, on this point, quotes Dr Macculloch, who supposed that these detached masses were merely fragments which had fallen from adjoining hills. But he admits that "the mode in which these fragments lie is remarkable. The bottom of the valley is covered with rocky eminences, of which the summits are not only bare, but often very narrow, while their declivities are steep and sometimes perpendicular. Upon these rocks the fragments lie, and in positions so extraordinary, that it is scarcely possible to conceive how they have risen so high after the rebound, or how they have remained balanced on the very verge of a precipice. One weighing about 10 tons has become a rocking stone. Another of not less than 50 tons stands on the narrow edge of a rock 100 feet higher than the ground below, which must first have met it in the descent" ("Western Islands," vol. i. p. 388).

One of these boulders, perched on the narrow edge of a rock,” was noticed by the Convener near where the boat takes passengers ashore at the head of Loch Scavaig. Fig. 48 represents this boulder-a shows its position relative to Lake Coruisk and the sea; b shows its position more exactly on the rock where it stands.

Dr Macculloch's idea of the boulder having fallen from an adjoining cliff, and rebounded on to the top of the rock where it stands, of course cannot be entertained.

On the other hand, if the boulder was brought by a glacier from

the eastward, and projected from the glacier's surface, would the boulder have rested where it fell? Is it not probable that it would have slid down the smooth rock into the sea?

The surface on which it lies, slopes steeply towards the sea, in a direction W. by N.; and under its S. E. end, there are two small boulders which seem to have obstructed progress in that direction. These circumstances conveyed to the Convener's mind the impression that the boulder may have been brought by floating ice, and been thus landed on the rock which it occupies.

It is right to add that the smoothed rocks, which occur near the shore adjoining the lake, have all the appearance of a great amphitheatre, into which floating ice may have entered, and in which ice may have circulated as in an eddy, abrading the rocks forming the bottom and sides of the amphitheatre.

This view of the matter is not inconsistent with the theory, that before the land was submerged, a glacier had existed in the valley, and formed smoothings and groovings also on the rocks as observed by Principal Forbes.

The Convener, seeing the importance of ascertaining beyond all doubt the true character of the materials forming the site of the "Big Boulder," in Barra (p. 122), wrote lately to Dr MacGillivray of Eoligarry, the tenant of the farm on which the boulder is situated, to request that he would dig under the boulder as far as could be done with safety, and send a written report of what was found. Since these sheets were printed, the Convener has received a letter, from which the following are extracts :

"Having at length got milder weather, we proceeded to the 'Big Boulder of the Glen,' and made the cuts or drains under it, as you directed, to the depth of three feet on both sides, and also at the west end of the boulder.

"The first substance found for about a foot deep, was black soil or earth and cockle-shells, mixed up with a few stones. Below that, as deep as we could conveniently go, very hard gravel and lumps of stone, extremely firm and difficult to pick out,-I should say, because being so much compressed by the enormous weight of the boulder.

"The rock of the hill did not appear at all on any side, or under the boulder for three feet at least. It seemed resting entirely on soil and gravel; site very high, almost on the surface, so that a spade can be pushed nearly to the centre in one or two places.

"The stone, to even an ordinary observer, would appear to have been brought to its present situation by some agency or other, as the place looks quite unnatural to it."

NOTES BY WILLIAM JOLLY, ESQ., INVERNESS, ON THE TRANSPORTATION OF ROCKS FOUND ON THE SOUTH SHORES OF THE MORAY FIRTH.

(Sent to Boulder Committee, October 1878.)

Along the south shores of the inner portion of the Moray Firth, certain movements of rocks have taken place in geological times which are interesting as bearing on the inquiry into the general transportation of boulders over Scotland. These rocks are, happily, of very distinctive varieties, which renders the question of their source and movements a comparatively easy one. On these, I beg to offer some rapid notes, in connection with the work of the Boulder Committee.

I. THE GRANITE OF THE DIRRIE MORE.

At the back of Ben Wyvis, on the road to Ullapool, between the Ben and Strath Vaich, there exists a development of a peculiar granite in situ, easily seen in passing along the road. The granite occupies a considerable area in the centre of the valley, and is seen in great extent in the bed of the river, to which it imparts a wild and picturesque character, as the water dashes and foams amongst its projecting masses. The rock consists of the usual ingredients of trinary granite, but its distinctive feature is the existence of lenticular pieces of dark mica, arranged throughout its pinkish mass in pretty regular layers, which give the rock somewhat of the general aspect of a stratified deposit. It is peculiar in general appearance, and is easily distinguished wherever seen by its kenspeckle character, even when not broken up. This rock is found scattered all over the country to the eastward of its parent position, and would seem to have been carried down the Blackwater valley in which it is found, and also right through the deep glen which exists in the very centre of the great bulk of Ben Wyvis, and which forms its most distinctive feature as seen from the Dirrie More, or Great Slope, as the long road to Ullapool is called. Thus viewed, Ben Wyvis seems cleft into two mighty masses by this great gorge, and has from this point, perhaps, its grandest and most commanding aspect. This granite is found scattered abundantly all over the Black Isle, where it exists as the most abundant surface rock, being imbedded in the debris and boulder clay that clothes the whole of