in Thoreau’s Journal:

From the entrance of the mill road, I look back through the sunlight, this soft afternoon, to some white pine tops near Jenny Dugan’s. Their flattish boughs rest stratum above stratum like a cloud, a green mackerel sky, hardly reminding me of the concealed earth so far beneath. They are like a flaky crust of the earth, a more ethereal, terebinthine, evergreen earth….My eyes nibble the piny sierra which makes the horizon’s edge as a hungry man nibbles a cracker.