PKOPOSED TIDAL HYDROELECTRIC POWER DEVELOP- 

 MENT OF THE PETITCODIAC AND MEMRAMCOOK 

 RIVERS 1 



By W. Rxjpebt Turnbull, F. R. Ae. S. 

 Rothesay, New Brunswick, Canada 



[With 1 plate] 

 HISTORICAL 



We should run over first and in a brief manner the tidal develop- 

 ments and proposals of the past, so that you will be led, as I have 

 been, to think that the first large tidal development in the world 

 will probably be carried out at Hopewell, the little village that lies 

 closest to the tidal estuaries, the Petitcodiac and Memramcook, 

 where nature has formed two great natural reservoirs, with the ex- 

 ception of the dams that must be built to complete them. 



Old charters show that tidal power was used in England for 

 grinding corn as early as the eleventh century and tidal mills have 

 been in operation for the same purpose from that time to the 

 present day. 



The following extracts are taken from an excellent article by 

 W. C. Horsnaill that appeared in The Engineer, London : 



No record exists showing how the earliest tide wheels were arranged, but 

 particulars are available of several mills which were erected in the eighteenth 

 and nineteenth centuries. In the earlier historic mills no attempts were 

 made to produce a fall, the power being obtained from the flow of the water 

 into and out of the pound. To develop power in this way a wheel similar 

 to the paddlewheels of steamships was used, but with a reversed action ; that 

 is to say, the flow of water drove the wheel. This arrangement entailed the 

 raising and lowering of the wheel to suit the rise and fall of the tide, as only 

 the bottom floats could be immersed if the best results were to be obtained. 



A corn mill at one time existed at East Greenwich which was driven by 

 tidal power in the way we have described. The pound had an area of about 

 4 acres and the wheel measured 11 feet in diameter by 12 feet long. The 

 power was transmitted by a bevel gear at either end of the water-wheel 

 shaft, the pinions being free to slide up and down two square vertical 

 spindles. The water wheel and bevel gears were mounted upon a frame 



1 Revision of paper read at the professional meeting of the Engineering Institute of 

 Canada, St. John. New Brunswick, Sept. 11, 1919. Reprinted by permission froni the 

 .Tournal of the Engineering Institute of Canada, October, 1919. 



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