536 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



propeller-type turbine (Moody diagonal propeller type), and we 

 consider this type here to afford a concrete example, the following 

 data being supplied by the company with special reference to this 

 particular type of turbine and the Hopewell conditions as to head, 

 etc.: 



Curves of the horsepower (average head case) and efficiency of 

 these turbines are given in Figure 6<?. and it will be noted that the 

 efficiency is high over a wide range of head, and that we might 

 expect a very good average efficiency from this type of turbine. 



The above data are tentative, but give a good idea of what can be 

 done by good low-head turbines, even over a wide range of head 

 variation. 



INITIAL AND FINAL DEVELOPMENTS 



The initial installation called for at the present time by the exist- 

 ing population would be about 90,000 gross horsepower, and we 

 note from Fig. 6<? that this corresponds to an hourly drop of 4.4 

 inches in the high-level basin. Now, while the population grew and 

 the demand for electricity increased from 90,000 upwards, we could 

 steadily be improving the ratio of the two basins, and thus greatly 

 improve our power output, up to, say, 200,000 horsepower. 



To improve this basin ratio to a better condition, in which the 

 Memramcook would have half the effective area of the Petitcodiac, I 

 propose to use electric shovels and an electric tramway, both operated 

 by surplus power from the initial installation, expropriate, by Gov- 

 ernment charter, the low-lying farms of the Memramcook Valley 

 at a fair and equitable rate, and shovel out the basin according to 

 power requirements, removing the material by the electric railway 

 and dumping it below the eastern dam, where it would be largely 

 carried away by the tide, or could be formed into a useful embank- 

 ment — wharf, railway terminal, or the like. 



A cheaper method of enlarging the Memramcook basin might be 

 to employ hydraulic excavation methods when this basin was being- 

 emptied, the water for this system being pumped when there was 



