Answer:
The Sea
Explanation:
We can find the answer in the following excerpt:
The gentleness of heaven broods o'er the Sea;
Listen! the mighty Being is awake,
And doth with his eternal motion make
A sound like thunder—everlastingly.
The author refers to the “mighty Being” that has an “eternal motion” and sounds “like thunder”; we can understand that the narrator is watching the sea and describing his behavior, the element of nature that refer to in the description is then the sea.
