head at French Corral was the height of the water in pen-stock above
the nozzle, no allowance being made (as in the North Bloomfield
experiments) for the loss of head by friction in pipes and by leakage.*
Curved Buckets.—Recent patterns of wheels with curved buckets have given an efficiency very much in excess of that described above.
Tests at the Idaho Mine.—A series of comparative tests was made in the spring of 1883 at the Idaho Mine,
All the data given on pages 189 and 190 concerning Hurdy-gurdy wheels
were communicated by the author to the American Institute of Mining
Engineers in a paper read at the Wilkesbarre meeting, May, 1877. See
vol. vi. " Trans. Amer. Inst. Mining Engineers."