That resemblance to an immense wave taking the precipice at one bound, bearing trees on its breast, fringed with the bushes, and winding out the long ivy sprays, which exhibit in their delicate tracery the form of the rigid glassy billow; that mere semblance of movement amidst the stillness and immovableness of death, and the presence of those two speechless creatures pursuing their ghastly work with automatic precision, added to the terror with which I already trembled.
Source: wiktionary