in Thoreau’s Journal:

How different is day from day! Yesterday the air was filled with a thick, fog-like haze, so that the sun did not once shine with ardor, and everything was so tempered under this thin veil that it was a luxury merely to be out doors. You were the less out for it. The shadows of the apple trees even early in the afternoon were remarkably distinct. The landscape wore a classic smoothness. Every object was as in a picture with a glass over it. I saw some hills on this side the river looking from Conantum, on which the grass being of a yellow tinge, though the sun did not shine out on them, they had the appearance of being shone upon peculiarly. It was merely an unusual yellow tint of the grass. The mere surface of the water was an object for the eye to linger on.

I thought that one peculiarity of my “Week” was its hypaethral character, to use an epithet applied to those Egyptian temples which are open to the heavens above, under the ether. I thought that it had little of the atmosphere of the house about it, but might have been written wholly, as in fact it was to a great extent, out of doors. It was only at a late period in writing it, as it happened, that I used any phrases implying that I lived in a house or led a domestic life. I trust it does not smell so much of the study and library, even of the poet’s attic, as of the fields and woods, that it is a hypaethral or unroofed book, lying open under the ether, and permeated by it, open to all weathers, not easy to be kept on a shelf.