TIDAL POWER — TURNBULL 525 



Mr. James Saunders discussed, in the Engineering Review of 

 London, three great plants for developments in England, viz, at 

 Chichester Harbor, at the Menai Straits, and in the Bristol Channel. 

 But in each case either the head of the water was too low or the 

 cost of forming the artificial reservoirs was too great to make the 

 proposals commercial at the present time. His most promising 

 scheme is that for the Bristol Channel, where the tidal head is 

 quite sufficient for successful operation, but where the cost of form- 

 ing the great artificial reservoirs that would be here required is 

 prohibitive in view of the power obtained. The total cost of the 

 plant figured out at $47,000,000 and the horsepower at 240,000, so 

 the cost per horsepower would be $196. 



C. A. Battiscombe, before London Society of Engineers, also 

 made a tidal proposal for the Bristol Channel, but his cost works 

 out at $237 per horsepower; and while neither of these figures 

 would be too high for commercial developments in some localities, 

 they are too high to interest English capital, for England is still 

 a country of cheap coal and in examining any hydroelectric de- 

 velopment we must constantly keep in mind the cost of power from 

 other sources. 



Mr. Boving has proposed a tidal plant for the River Dee, but no 

 estimates of costs are given; and coming nearer home, there have 

 been numerous proposals for obtaining power from the tides at Sack- 

 ville, at Cape Split, and at the Reversible Falls of St. John. 



Now to get continuous power at any of these sites, it would be neces- 

 sary to form large artificial reservoirs, and the formation of such 

 reservoirs is so costly that these proposals are not, at present, com- 

 mercially feasible. 



DESIDERATA FOR A TIDAL PLANT 



The three great desiderata for a tidal plant are : First, that there 

 should be sufficient height of tide to obtain a good head ; second, that 

 there should be two natural reservoirs of large size so that continuous 

 power can be obtained; and, third, that the power plant should be 

 central to the population that would be served. 



And it is these three desiderata that lead us to suppose that the first 

 great tidal development in the world will take place at Hopewell. 

 Here we have two large reservoirs almost completely formed by 

 nature, we have a tide which is exceedingly regular and that ranks 

 among the highest tides in the world, with a spring rise of 45 feet, 

 a neap rise of 38 feet, and a normal neap range of 32 feet, and we 

 have this power centrally located to a present population of 250,000 

 who are literally starving for cheap electric power, with no other 

 hydroelectric developments in sight, except small ones and those that 



