He wrapt his cloak around him, fell asleep, and dreamed of Lucy Ashton till daylight gleamed through the lattices.

'Twas night; on earth all creatures were asleep, / when lo! the figures of our gods, the same / whom erst from falling Ilion o'er the deep / I brought, scarce rescued from the midmost flame, / before me, sleepless for my country's shame, / stood plain, in plenteousness of light confessed, / where streaming through the sunken lattice came / the moon's full splendour, and their speech addressed, / and I in heart took comfort, hearing their behest.

A lattice is an abstract structure studied in the mathematical subdisciplines of order theory and abstract algebra.

In algebra, abstract algebra is the study of algebraic structures. Algebraic structures include groups, rings, fields, modules, vector spaces, and lattices.