CHAP. IX. RENNIE'S WAR DOCKS. 235 



CHAPTER IX. 



MR. RENNIE'S WAR DOCKS AND OTHER GOVERNMENT WORKS. 



FROM an early period Mr. Rennie's eminent practical 

 abilities pointed him out for employment in the public 

 service ; and he was consulted by the Ministry of the day 

 more particularly as to the machinery used in the Govern- 

 ment establishments, the formation of royal docks, and 

 the construction of breakwaters. At the recommenda- 

 tion of Mr. Smeaton he was called upon by the Vic- 

 tualling Department of the Navy to advise them as to 

 the improvement of their flour -mills at Rotherhithe, 

 which were worked by the rise and fall of the tide ; and 

 the manner in which he performed that service was so 

 satisfactory, that it shortly led to his advice being taken 

 on other subjects, some of which might at first sight be 

 supposed to lie beyond the range of his engineering 

 experience. 



Great alarm prevailed in 1803 as to the threatened 

 intentions of our warlike neighbours across the Chan- 

 nel. The ' Moniteur ' and the ' Brussels Gazette ' were 

 openly speculating as to the time it would take the 

 French army to reach London, and it therefore be- 

 hoved England to be upon her guard. All the possible 

 lines of approach from the coast to the capital were 

 carefully examined ; and it appeared to military men 

 that the eastern side of London was the most acces- 

 sible to the advance of an enemy landing near the 

 mouth of the Thames or on the Essex coast. Mr. 

 Rennie was employed to examine the valley of the Lea, 

 to ascertain whether means could be devised for sud- 



