The mysteries of udulpho essays

What is the “narrow cell” in line 15 of “elegy written in a country churchyard”

When first i engaged in this work, i resolved to leave neither words nor things unexamined, and myself with a prospect of the hours which i should revel away in feasts of literature . . –preface to a dictionary of the english language, samuel johnson what is the connotation of the word revel in this passage?

By comparing part 1 and 2 of polar opposites what does it mean by polar opposites