388 BATHYMETRICAL SURVEY OF 



cent. In Loch Ericht the shore-zone is equal to 34 per cent., the second 

 zone between 100 and 200 feet is equal to 25 per cent., and the third 

 zone between 200 and 300 feet is equal to 19 per cent, of the total area, 

 the deeper zones in each case not exceeding 10 per cent. In Loch Tay 

 there is a regularly decreasing percentage in the zones of depth from 

 the shore into deep water, the numbers for each zone at intervals of 

 100 feet being respectively 30, 23J, 21, 15J, 9. 



Loch Quoich (see Plate XCIIL). The largest loch in the basin after 

 Loch Ness. It is very nearly 7 miles in length, and occupies the upper 

 part of Glen Garry, which here runs east and west. It is 9 miles west 

 of Loch Garry, and 15 miles from Loch Oich. It is much nearer the 

 west coast, the head of Loch Hourn being only 4 miles distant. The 

 mountain peaks both north and south reach well over 3000 feet. On 

 the south the highest peak is Sgor Mor (3290 feet). On the north 

 the two peaks of Sgurr a' Mhoraire (3365 feet) and Gleourach (3395 

 feet) rise to the west and east of Glen Quoich, which branches north- 

 ward from Glen Garry about the middle of Loch Quoich. On the 

 north Loch Quoich is densely wooded for the greater part of its length. 



Loch Quoich is of the usual elongate form of Scottish glen lochs. 

 Its central line is strongly curved, the central part further north than 

 the ends. The height of the loch above sea-level on May 6, 1903, was 

 556-0 feet; the Ordnance Survey officers, on August 24, 1867, found it 

 to be 555-3 feet. The length, measured in a straight line between the 

 ends, is almost exactly 6 miles; measured along the centre line it is 

 nearly 7 miles. The maximum breadth of three-quarters of a mile 

 occurs just east of the centre. The mean breadth is a little under half 

 a mile. The superficial area of the loch is about 1833 acres, or fully 

 2| square miles, and it contains 8345 millions of cubic feet of water, 

 more than twice the volume of Loch Garry, the loch next to it in size. 



Loch Quoich drains an area of 49 square miles, which includes no 

 large lochs, but some very small ones which were not surveyed. Several 

 large burns, rising among the high mountains of the west, enter at the 

 head of the loch; and the Caolie water, flowing in on the north shore, 

 is a fair stream ; but the most important inflowing river is the Quoich, 

 which enters about the middle of the north side, and has here by its 

 delta effected a considerable narrowing of the loch. The constriction 

 so produced is the greater because, just opposite the mouth of the river, 

 a high promontory juts out more than a quarter of a mile from the 

 south shore. The shallowing of this constriction is but slight. 



The basin of Loch Quoich is simple, with steep and nearly uniformly 

 sloping sides, and very little flat bottom. The contours are all con- 

 tinuous and approximately parallel with the shore-line, except the 

 200-feet contour, which is slightly interrupted by a shallowing where 

 the maximum is 190 feet, just west of the mouth of the Quoich. The 



