Here in New England, each season carries a hundred foreshadowings of the season that is to follow -- which is one of the things I love about it. Winter is rough and long, but spring lies all round about. Yesterday, a small white keel feather escaped from my goose and lodged in the bank boughs near the kitchen porch, where I spied it as I came home in the cold twilight. The minute I saw the feather, I was projected into May, knowing that a barn swallow would be along to claim the prize and use it to decorate the front edge of its nest. Immediately, the December air seemed full of wings of swallows and the warmth of barns. Swallows, I have noticed, never use any feather but a white one in their nest-building, and they always leave a lot of it showing, which makes me believe that they are interested not in the feather's insulating power but in its reflecting power, so that when they skim into the dark barn from the bright outdoors they will have a beacon to steer by.

为了大家方便，附上几个不特别常用的单词意思：
keel feather：大羽毛，keel是龙骨，可以指船的龙骨什么的
goose是鹅，keel feather是鹅的那种长羽毛
bank boughs可能是指厨房廊子旁边堆的柴火，bank堆积，bough是树枝。
barn是谷仓
swallow是燕子，这里燕子在怀特家的谷仓做了窝
insulate保温 隔热
reflect反光
skim掠过
beacon灯塔
steer驾驶 航行 开车等