THE TWEED 25 



is considerable. Rather more than half way to the mouth, the 

 Whitadder tributary enters on the left side. It rises away in 

 East Lothian on the slopes of the Lammermoors and has a 

 course of about 38 miles. The last two miles are in England, 

 for the Tweed before the junction is reached has passed wholly 

 out of Scotland. The line of the Whitadder, and its erosion 

 of the old land surface, forms a natural passage from the Borders 

 towards Edinburgh, and a chain of castles formerly guarded 

 this line as similar structures already referred to kept watch 

 over Tweedside. The river does not become of any great size 

 till Abbey St. Bathans is reached, a former Cistercian settle- 

 ment now no longer in existence. The country is typical of 

 Berwickshire, with its undulating stretches of highly farmed 

 land interspersed with woods and fertile meadows. Cock- 

 burn's Law, close to the river, is a well-marked feature and is 

 interesting to geologists as a granite cone resting on the 

 greywacke of the surrounding country. 



At CMrnslde the Whitadder is joined by the Blackadder, 

 another stream of considerable length some 16 miles wholly 

 in Berwickshire. It rises in the parish of Westruther on the 

 southern slopes of the Lammermoors, which divide the head 

 streams from Lauderdale. It flows eas!t by Greenlaw in a 

 direction almost parallel to Tweed, and thus joining the south- 

 coming Whitadder at a rather abrupt angle. Sir Thomas 

 Dick Lauder, 1 speaking of Westruther parish, quotes an inter- 

 esting passage from the Statistical Account which in explaining 

 that the name was originally Wolfstruther, or Wolf's Swamp, 

 speaks of it " as a place of old which had great woods, with 

 wild beasts, fra quhilk the dwellings and hills were designed as 

 Wolfstruther, Roecleugh, Bindside, Hartlaw, and Harelaw." 



There are nine weirs on the Whitadder and two on the 

 Blackadder, but none of them need be regarded as very serious 

 obstacles to ascending fish, in spite of the fact that only one, 

 at Chirnside, has a pass. The paper works at Chirnside are 

 provided with nine setting tanks and a filter of ashes, so that 

 a great part of the deleterious matter is kept from the effluent. 

 At Cumledge, on the river above Chirnside, the woollen mills 

 have also tanks, where the effluent is treated with sulphuric 

 acid and neutralised. At Greenlaw, on the Blackadder, 

 1 Scottish Rivers, 1890, p. 254. 



