J44 SCIENCE. [x. 



years as one day. I believe this dread of size to be 

 merely, like all other superstitions, a result of bodily 

 fear; a development of the instinct which makes a 

 little dog run away from a big dog. Be that as 

 it may, every observer has it ; and so the man's 

 conclusion seems to him strange, doubtful : he will 

 reconsider it. 



Moreover, if he be an experienced man, he is well 

 aware that first guesses, first hypotheses, are not always 

 the right ones ; and if he be a modest man, he will 

 consider the fact that many thousands of thoughtful 

 men in all ages, and many thousands still, would say, 

 that the glen can only be a few thousand, or possibly 

 a few hundred, years old. And he will feel bound to 

 consider their opinion ; as far as it is, like his own, 

 drawn from facts, but no further. 



So he casts about for all other methods by which 

 the glen may have been produced, to see if any one of 

 them will account for it in a shorter time. 



1. Was it made by an earthquake ? No; for the 

 strata on both sides are identical, at the same level, 

 and in the same plane. 



2. Or by a mighty current ? If so, the flood must 

 have run in at the upper end, before it ran out at the 

 lower. But nothing has run in at the upper end. All 

 round above are the undisturbed gravel-beds of the 

 horizontal moor, without channel or depression. 



3. Or by water draining off a vast flat as it was 

 upheaved out of the sea ? That is a likely guess. The 

 valley at its upper end spreads out like the fingers of a 

 hand, as the gullies in tide-muds do. 



But that hypothesis will not stand. There is no 

 vast unbroken flat behind the glen. Eight and left of 



