Book,  Chapter

 1        I,  VI  | opposite horizon, it seemed to retreat farther off, grew dimmer,
 2        I,  XX  |       search of some available retreat. Scarcely a yard of ground
 3       II,  XI  |     the gloomy recesses of his retreat.~To Ben Zoof the last week
 4       II,  XII | companions were glad enough to retreat.~Here they found the professor,
 5       II,  XII |     fain to make a precipitate retreat from his observatory. Now
 6       II,  XII | prosecute his labors so that a retreat might be immediately effected
 7       II,  XII |        find himself obliged to retreat from his study of the heavens,
 8       II,  XIII|       was the desire to find a retreat for every living thing in
 9       II,  XIII|     elapse before any place of retreat could be discovered likely
10       II,  XIV |     warmth of the subterranean retreat for the more airy and commodious