INJUBIOUS EFFECTS OF HEAVY SPATES. 63 



Strongly, however, as all these causes operate, there 

 is one more destructive than all of them put together; 

 namely, the effects of the furious spates which are 

 continually taking place in the Tweed, and which put 

 the channel in motion, and often sweep away the 

 spawning beds altogether. 



Before the hills were so well drained as at present, 

 this was not so much the case ; as the mosses gave out 

 the water gradually, and the river continued full for a 

 long time, to the great solace of the rod fisher. But 

 now every hill is scored with little rills which fall into 

 the burns, which suddenly become rapid torrents and 

 swell the main river, which dashes down to the ocean 

 with tremendous violence. Amidst the great din, you 

 may hear the rattling of the channel stones, as they 

 are borne downwards. Banks are torn away ; new 

 deeps are hollowed out, and old ones filled up ; so that 

 great changes continually take place in the bed of the 

 river either for the better or the worse. 



When we contemplate these things, we must at once 

 acknowledge the vast importance of Mr. Shaw's experi- 

 ments ; for if ponds were constructed up the Tweed 

 at the general expense, after the model of those made 

 by him, all these evils would be avoided. The fry 

 might be produced in any quantities by artificial im- 

 pregnation ; be preserved, and turned into the great 

 river at the proper period of migration. There might 

 at first be some difficulty in procuring food for them ; 

 but this would easily be got over. At a very small 

 expense, and with a few adult Salmon, more fry may 

 be sent to sea annually than the whole produce of the 



