Aside from personal glory, what two benefits to mankind does Walton hope to achieve in Frankenstein?

Robert Walton, the sailor we meet in the letters at the beginning of the book and to whom we return at the end of the book, is looking for a passage through the North Pole.  In fact, he says in a letter to his sister,

"I shall satiate my ardent curiosity with the sight of a part of the world never before visited, and may tread a land never before imprinted by the foot of man" (page 26 in the Bedford St. Martin edition).

So, he does hope to gain personal glory, but through some sea passage through the North Pole that ships can pass through instead of having to go around saving time, money and resources.  He also hopes to put his "imprint" on lands that have never before been seen or touched by humankind.  Perhaps to discover some other thing--an animal, a continent, some object that will make him famous for having discovered it.

Little does he know that his greatest contribution will be after he meets Victor and they converse, thus "teaching" readers of the journal he publishes how to act and what not to do.