THE FRESH- WATER LOCHS OF SCOTLAND. 349 



Banchron) lies less than a mile to the east of Loch a' Mhuilinn and 

 about 6 miles east of Loch Monar, and is the final one of the series of 

 lochs in Glen Strath Farrar. The shores are mostly of gravelly debris, 

 forming terraces about 20 feet high, which are best seen along the south 

 shore; the surrounding hills are high and rugged, and well wooded. 

 The loch trends east-north-east and west-south-west, and is 1J miles in 

 length, with a maximum width of nearly one-third of a mile, the 

 superficial area being about 157 acres, or a quarter of a square mile. 

 The area draining directly into Loch Bunacharan is only about 4 square 

 miles, but it receives the overflow from Lochs Calavie, an Tachdaidh, 

 an Gead, Monar, and a' Mhuilinn, and its total drainage area is there- 

 fore a very large one about- 92 square miles. The maximum depth of 

 113 feet was observed towards the east end of the loch less than 

 half a mile from the east end and more than three-quarters of a mile 

 from the west end. The volume of water is estimated at about 343 

 million cubic feet, and the mean depth at over 50 feet. The loch was 

 surveyed on October 12, 1903, when the elevation of the lake-surface 

 above the sea was found, by levelling from bench-mark, to be 366*15 

 feet; when levelled by the officers of the Ordnance Survey on June 9, 

 1866, the elevation was 366-5 feet above sea-level. On the date of the 

 survey the water was about its normal level, and a recent drift-mark 

 was observed 9 feet above the surface of the water, while an older drift- 

 mark was 11 feet above the water-surface. 



Loch Bunacharan is irregular in conformation, the lake-floor in the 

 deeper part of the loch rising and falling in a series of undulations. 

 The 25-feet and 50-feet contours are continuous from end to end of the 

 loch, and coincide approximately with the shore-line. The 75-feet 

 contour, however, encloses three distinct basins separated from each 

 other by shallower water, viz. (1) a very small basin based on a 

 sounding in 83 feet about 300 yards from the western end ; (2) a larger 

 basin a quarter of a mile in length, and trending almost north and 

 south, i.e., transversely across the loch, based 011 soundings in 78, 82, 

 and 88 feet, situated about one-third of a mile from the western end ; 

 and (3) the largest and deepest basin, one-third of a mile in length, 

 approaching to within a quarter of a mile from the eastern end, and 

 enclosing a small basin exceeding 100 feet in depth, based on soundings 

 in 105, 111, and 113 feet. Between the second and third basins above 

 noted there is a rise of the lake-floor near the middle of the loch, 

 covered by 43 feet of water, surrounded on all sides by deeper water. 

 These inequalities are indicated to some extent in the longitudinal 

 section A-B on the map, taken along the axis of maximum depth, but 

 most of the cross-lines of soundings show a regular bottom, as shown in 

 cross-section C-D, taken at the position of the deepest sounding. The 

 slope of the bottom seems to be gentle on the whole, the steepest 

 gradient observed being off the northern shore towards the west end, 



