160 RENNIE'S DRAINAGE OF PART VII. 



they burst the defensive banks of the rivers, and an 

 amount of mischief was thus done which the drainage of 

 all the succeeding summer failed to repair. Accordingly, 

 the next essential part of Mr. Eennie's scheme was the 

 provision of more effectual outfalls ; with which object he 

 designed that they should be cut down to the lowest 

 possible level of low water, whilst he arranged that at 

 the points of outlet they should be mounted with strong 

 sluices, opening outwards ; so that, whilst the fresh waters 

 should be allowed freely to escape, the sea should be 

 valved back and prevented flowing in upon the land. 

 The third and last point was to provide for the drainage 

 of the Fen districts themselves by means of proper cuts 

 and conduits for the voidance of the Fen waters. 



Such were the general conclusions formed by Mr. 

 Eennie after a careful consideration of the circumstances 

 of the case, which he embodied in his report to the 

 Wildmore Fen proprietors * as the result of his investi- 

 gations. The two great features of his plan, it will be 

 observed, were (1) his intercepting or catch water drains, 

 and (2) his cutting down the outfalls to lower levels 

 than had ever before been proposed. Simple though his 

 system appears, now that its efficacy has been so amply 

 proved by experience, it was regarded at the time as 

 a valuable discovery in the practice of fen-draining, 

 and indeed it was nothing less. There were, however, 

 plenty of detractors, who alleged that it was nothing of 

 the kind. Any boy, they said, who has played at dirt 

 pies in a gutter, knows that if you make an opening 

 sufficiently low to let the whole contained water escape, 

 it will flow away. Yery true ; yet the thing had never 

 been done until Mr. Rennie proposed it, and, simple 

 though the method was, it cost him many years of 

 arguing, illustration, and enforcement, before he could 

 induce intelligent men in other districts to adopt the 



1 Report, dated the 7th of April, 1800, 



