386 



General Results of a Gardening Tour : — 



Greenock ; and each of 

 these reservoirs is capa- 

 ble of containing a sup- 

 ply for the consumption 

 of the inhabitants, for 

 more than six months ; 

 " so that not only the 

 surplus waters of one 

 wet season may be re- 

 tained for supplying the 

 dry season of the same 

 year, but the surplus of 

 several wet years may 

 be stored up to supply 

 a drought of several 

 years' duration, should 

 such ever occur." The 

 water is brought to the 

 summit of the hill in 

 such a quantity as to 

 supply 1200 cubic feet 

 per minute, which Mr. 

 Thorn estimates, on a 

 fall of 30 ft., as equal to 

 a Bolton and Watt's 

 steam-engine of fifty- 

 horse power. In what 

 manner the water is ap- 

 plied in succession to 

 the mills, will be easily 

 understood by the in- 

 spection of Jig. 63., 

 which is an imaginary 

 section from the summit 

 of the hill (a), through 

 all the water-wheels, to 

 high watermark on the 

 Clyde (b). The line 

 of wheels dotted, shows 

 that there are two series 

 of situations for mills. 

 The same aqueduct sup- 

 plies water for the in- 

 habitants at the rate of 

 2 cubic feet per head 

 per day. 



