144 FRAGMENTS OF SCIENCE. 



sudden bend to the northeast, forming nearly a right 

 angle with its previous direction. The water strikes tlio 

 concave bank with great force, and scoops it incessantly 

 away. A vast basin has been thus formed, in which the 

 sweep of the river prolongs itself in gyratory currents. 

 Bodies and trees which have come over the falls, are stated 

 to circulate here for days without finding the outlet. From 

 various points of the cliffs above, this is curiously hidden. 

 The rush of the river into the whirlpool is obvious enough; 

 and though you imagine the outlet must be visible, if one 

 existed, you cannot find it. Turning, however, round the 

 bend of the precipice to the northeast, the outlet comes 

 into view. 



The Niagara season was over; the chatter of sightseers 

 had ceased, and the scene presented itself as one of holy 

 seclusion and beauty. I went down to the river's edge, 

 where the weird loneliness seemed to increase. The basin 

 is enclosed by high and almost precipitous banks covered, 

 at the time, with russet woods. A kind of mystery attaches 

 itself to gyrating water, due perhaps to the fact that we 

 are to some extent ignorant of the direction of its force. 

 It is said that at certain points of the whirlpool, pine trees 

 are sucked down, to be ejected mysteriously elsewhere. 

 The water is of the brightest emerald-green. The gorge 

 through which it escapes is narrow, and the motion of the 

 river swift though silent. The surface is steeply inclined, 

 but it is perfectly unbroken. There are no lateral waves, 

 no ripples with their breaking bubbles to raise a murmur; 

 while the depth is here too great to allow the inequality of 

 the bed to ruffle the surface. Nothing can be more beauti- 

 ful than this sloping liquid mirror formed by the Niagara, 

 in sliding from the whirlpool. 



The green color is, I think, correctly accounted for in 

 the last Fragment. While crossing the Atlantic in 1872-73 

 I had frequent opportunities of testing the explanation 

 there given. Looked properly down upon, there are 

 portions of the ocean to which we should hardly ascribe a 

 trace of blue; at the most, a mere hint of indigo reaches 

 the eye. The water, indeed, is practically black, and this 

 is an indication both of its depth and of its freedom from 

 mechanically suspended matter. In small thicknesses 

 water is sensibly transparent to all kinds of light; but, as 

 the thickness increases, the rays of low refrangibility are 



