THE CHARM OF THE WATER-FALL 



Naturally it causes a washout over the insecure por- 

 tion where no provision had been made for an over- 

 flow. The washout broadens and deepens until the 

 dam weakens and ' ' bursts ' ' at this point. The whole 

 trouble might have been saved had the spillway been 

 constructed to receive not alone the usual flow of 

 water, but to provide for excess in every possible 

 emergency. 



To insure permanency of the water-fall, and a 

 comparatively even overflow without extra dash and 

 beauty (and consequent worry) in times of storm, it 

 will be best to provide a gate in the dam of unusual 

 dimensions, This will not only make it possible to 

 let out the excess of water during freshets, but it is 

 also useful for drawing off the lake when necessary. 

 For the shallow lake and small dam, the gate will not 

 be required. If the spillway is built of non-washable 

 material, and is built adequate for abnormal de- 

 mands, this will prove entirely satisfactory ; and the 

 gate will prove only an additional expense. There 

 may be a temptation to have the spillway too narrow 

 for emergency use, because it will provide an extra 

 dash and rush of water to beautify the water-fall. 

 But it will be better to provide for this dash and 

 sparkle by having the overflow roughened with jut- 

 ting stones, or some clever device in masonry, while 



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