236 COAST DEFENCES. TART VII. 



denly laying it under water, if necessary, to check the 

 approach of a hostile army from that quarter. After 

 careful consideration, he laid before the Government 

 a plan with that object, which included a series of 

 dams furnished with sluices, one at the junction of 

 the Lea with the Thames, another across the valley at 

 Bow, a third at Temple Mills, and others higher up 

 the river as far as Amwell. These were contrived so 

 that the waters should be penned up, and the valley 

 flooded at will. The works were, however, only partially 

 carried out, and some five dams were formed above 

 Bromley, with jetties at different points to increase the 

 current ; but happily these defensive works were never 

 required, Napoleon's warlike ambition having shortly 

 after become diverted in another direction. 



About the same time Mr. Rennie was consulted as to 

 the best means of improving the defences of the coast 

 of Kent ; and he laid out and constructed for the Go- 

 vernment the Hythe Military Canal, defended by earth- 

 works, and protected by a breastwork on the land 

 side. It extends for some twenty miles westward across 

 Bomney Marsh to the river Bother, near Bye. 1 He 

 was also consulted as to the best site for a low-water 

 harbour on the south-east coast for accommodating 

 frigates to watch the opposite shore, Napoleon's legions 

 being then assembled on the heights above Boulogne, 

 and his fla1>bottomed boats crowding its port. Mr. 

 Bennie's opinion was in favour of Folkestone as the 

 best site for such a port, where a ridge of rocks outside 

 its then small tidal basin offered unusual facilities for 

 the formation of a haven capable of accommodating 

 vessels of considerable burden. This work was not, 

 however, carried out, and Folkestone Harbour is happily 

 now devoted to more pacific purposes. 2 



1 See Descriptive View of Romney I 2 Mr. Rennie seems to have been 

 Marsh, Vol. I., p. 8. | frequently in communication with 



