love's meinie. 55 



one is on all sides with pitfalls for the theorists. The 

 forked tail reminds you at once of a fish's ; and yet, the 

 action of the two creatures is wholly contrary. A fish 

 lashes himself forward with his tail, and steers with his 

 fins; a swallow lashes himself forward with his fins, and 

 steers with his tail ; partly, not necessarily, because in 

 the most dashing of the swallows, the swift, the fork of 

 the tail is the least developed. And I never watch the 

 bird for a moment without finding myself in some fresh 

 puzzle out of which there is no clue in the scientific 

 books. I want to know, for instance, how the bird turns. 

 What does it do with one wing, what wdth the other ? 

 Fancy the pace that has to be stopped; the force of 

 bridle-hand put out in an instant. Fancy how^ the wings 

 must bend with the strain ; what need there must be for 

 the perfect aid and work of every feather in them. 

 There is a problem for you, students of mechanics, — How 

 does a swallow turn ? 



You shall see, at all events, to begin with, to-day, how 

 it gets along. 



65. I say you shall see ; but indeed you have often 

 seen, and felt, — at least with your hands, if not with your 

 shoulders, — when you chanced to be holding the sheet of 

 a sail. 



I have said that I never got into scraj^es by blaming 

 people wrongly; but I often do by praising tliem wrongly. 

 I never praised, without qualification, but one scientific 

 book in my life (that I remember) — this of Dr. Petti- 



