134 



BATHYMETRICAL SURVEY OF 



LOCHS OF THE TWEED BASIN 



THE large area drained by the river Tweed (see Index Map, Fig. 15) 

 is on the whole remarkably devoid of lochs. It is true there are a dozen 

 little lochs on the borders of Roxburghshire and Selkirkshire, drained by 

 the Teviot branch of the Tweed, but they are very small, and were not 

 sounded by the Lake Survey. The principal loch is the well-known 

 St. Mary's Loch, with the adjacent Loch of the Lowes, in Selkirkshire, on 



English Miles 



Bartholomew. 



O S 10 ZQ 30 



FIG. 15. INDEX MAP OF THE TWEED BASIN. 



the Yarrow branch of the Tweed, while a notable addition has recently 

 been made by the construction, for the supply of water to the city of 

 Edinburgh and surrounding district, of the Talla reservoir in Peebles- 

 shire, which lies about 6 miles west of St. Mary's Loch, on the Talla 

 branch of the Tweed. Of the three lochs surveyed, St. Mary's Loch is the 

 largest and the Loch of the Lowes the smallest, Talla reservoir being 

 intermediate in point of size : St. Mary's Loch slightly exceeds 3 miles in 

 length, Talla reservoir is nearly 2J miles in length, while the Loch of the 

 Lowes is less than a mile in length ; the superficial area of St! Mary's 



