transom-window

For in one corner of my room I boast of a prize dusty "cobweb," as yet spared from the household broom, a gossamer arena of two years 'standing, which makes a dense span of a length of about two feet from a clump of dried hydrangea blossoms to the sill of a transom-window, and which, of course, somewhere in its dusty spread, tapers off into a dark tunnel, where lurks the eight-eyed schemer, "o'erlooking all his waving snares around."

My Studio Neighbors William Hamilton Gibson 1873