Get out the microscope, because we’re going through this poem line-by-line.
[…] He learned all there was
To learn about not launching out too soon
And so not carrying the tree away
Clear to the ground […]
- The boy starts to get better about swinging the trees over time.
- He learns to get all the way to the top of the tree and not bend it too soon, before he's reached the top.
- If he did jump out too soon, the tree would be damaged.
- If you're a science person, think of this as a Physics lesson combined with a Biology lesson: the tree is a flexible lever; the roots are the fulcrum; the boy is the load.
[…] He always kept his poise
To the top branches, climbing carefully
With the same pains you use to fill a cup
Up to the brim, and even above the brim.
- Now we're getting some details of how the boy becomes better at swinging the trees.
- He keeps "his poise," meaning he stays balanced and calm, sort of hovering up on a tree branch.
- The speaker compares it to filling a cup to the brim. If you are pouring liquid into a cup, you are so careful not to overflow the cup, so you add a small amount of the liquid at a time. Then you add just a teeny bit more and the liquid forms a dome just above the rim of the cup.
- Think of this one as a Chemistry lesson. Are you beginning to notice that nature and science play important roles in this Frost poem?
Then he flung outward, feet first, with a swish,
Kicking his was down through the air to the ground.
- The boy has filled the metaphorical cup above the brim and has now reached the top of the tree.
- Next he kicks his feet out (presumably holding onto a branch) and uses the tree like a bungee chord.
- The tree bends just enough so that the boy is lowered to the ground without harm.