58 



Papers connected ivith the construction [No. 31 



advantage of the alternations in the different rises and falls of the tides and 

 kind-floods, to preserve this channel so guarded against the surf free from 

 any deposition, by suffering at pleasure a torrent to pass through, and this 

 always leaves a backwater at command, which if properly managed, will 

 afford I imagine an adequate remedy for the evil. 



It was first my idea that in order to form a perfect communication for 

 boatf and small crafts at all times into the river, it would be necessary to 

 construct a double set of gates in both directions, so as to establish a 

 pond to be used against both tides and land floods, but upon closer 

 observation it appeared to me to be unnecessary, as no material inconveni- 

 ence can ever arise from boats being obliged to wait the hours of the 

 tides to pass in or out, and during the continuance of the land-floods, 

 there are generally so few vessels at Madras, that the communication may 

 be easily dispensed with for so short a time, particularly when it is taken 

 into the account, that a considerable increase of the expence must attend 

 that addition to the plan. 



• 



In forming this design, I have endeavoured to unite what is practicable, 

 without extraordinary trouble and expence, with what is desirable. The 

 difficulty and danger of the present communication are generally admit- 

 ted. To render a passage safe and easy for vessels of large size and great 

 draught of water, though perhaps possible, would, I apprehend, be 

 attended with such a great expence, as probably to amount to a prohibition. 

 There must be an artificial management of a backwater, to keep any 

 confined channel towards the sea, clear of the deposition of sand which 

 would be a natural consequence of such enclosure. In order, then, to 

 accomplish such backw r ater. sluices are indispensably necessary, and thes e 

 when carried beyond a certain scale and extent, would not only require a 

 vast increase of expence in the execution, but be attended with consider- 

 able difficulty in the management, besides being much more liable to 

 accident, 



Guided by these reflections, I therefore conceived that it would fulfil 

 every moderate expectation, to effect a safe and easy passage for long 

 boats of Men of War, and Indiamen, at the lowest tides ; and when the 

 tide was in, even for the common Donies and small craft that bring rice 

 and other grain along the coast. The plan No. 3 intended to produce 

 this beneficial consequence, consists of a series of sluices, each of twenty 

 feet wide, and the floors sunk to six feet below low water at spring tides, 

 with double gates so as to command a backwater in both directions. 



