Il était impossible = Il aurait été impossible

16. un lieu qui promît au voyageur. The subjunctive ( Outline , II, B, 1) is here used in a relative clause of characteristic, that is, one which modifies an indefinite antecedent described as desired or thought of, but not as found.

18. un sable blanc comme la neige. Note that here, as often, both un (“ a kind of ”) and la are to be omitted in translation. French uses many more articles, both definite and indefinite, than English does.