Robert Walton is an explorer. On the particular voyage that forms the basis of the story's frame narrative, he is heading off to the icy wastes of the North Pole in search of uncharted lands and the knowledge they will bring.

Though a somewhat isolated individual, Walton isn't just in this for personal glory; he hopes that his expeditions will ultimately push back the frontiers of scientific knowledge, thus benefitting humankind as a whole.

This stands in stark contrast to Victor Frankenstein. While conducting his dangerous experiments, he seems himself almost like a god.

Frankenstein has such an unhealthy obsession with achieving his goal that he doesn't think through the consequences of his actions. It's only later on, after the creature comes to life and eventually goes on the rampage, that its reckless creator starts to realize just what he's done.

Even so, there are enough similarities between Walton and Frankenstein to make them bond immediately. Both are men of science, both are solitary men, and both find purpose in the process of scientific discovery. That is why Walton has embarked upon this treacherous, potentially perilous journey to the North Pole.

But unlike Frankenstein, he's not prepared to take crazy, irresponsible risks in order to fulfill his objectives. He knows when to let go. In this sense, Walton serves as a foil to Frankenstein, the very epitome of the “mad scientist” stereotype.

While Walton is not a major figure in Mary Shelley's Frankenstein, he does serve an important purpose in paralleling the character and desires of the novel's protagonist, Victor Frankenstein. Walton wants to be a great man whose name goes down in history. He wants to be remembered for historic achievements. His journey into the north is meant to be his ticket to fame.

Specifically, Walton wants to discover uncharted territory and to be the first human being to set foot there. Additionally, he claims he wants to learn "the wondrous power which attracts the needle," that is, what force influences compass needles. All of this would grant him a sense of importance. In his letters to his sister, Walton reveals an additional motivator: the desire to impress his family. His father in particular has no faith in his capacity to make a career at sea, so Walton is hoping to make good by becoming an explorer.

Naturally, Walton's desires for fame and greatness parallel Frankenstein's dream to conquer death through science. When Frankenstein appears and shares his sad tale, he serves as Walton's most immediate model for the pursuit of ambition gone mad. However, Walton turns out to be cut from a different cloth than Frankenstein: though the dying Frankenstein urges Walton to keep going with his hopeless expedition, Walton ultimately gives it up. Perhaps Frankenstein's fate made the quest for glory far less appealing.

Mary Shelley's Frankenstein includes a series of letters which affect the events in the story. The first of these, written by an explorer named Robert Walton to his sister back in England, Mrs. Saville, is sent from St. Petersburg, Russia and discusses Walton's upcoming voyage to the North Pole. He reveals that he has spent six years preparing for and planning this trip, and that he plans to leave the following June. He will soon make a trip to Russia to find the right ship for the voyage and to finalize plans for the journey.

Walton recalls his father telling his uncle that Walton should not be a sailor. He also recounts his failure to make a career out of writing poetry. These are two motivations for his expedition: to prove his family wrong and to make up for his previous failures. He implies in his letter to his sister that he wants to know and learn more about the world, and that he cannot learn these things sitting at home and writing about them.

In summary, Walton desires to take this trip in order to show his father and uncle, as well as himself, that he can do something of worth and importance to the world. He can discover new things and learn new information to share with others. His self-image and his persona to others will undertake a transformation, should he return alive and successful.

In Letter One, of Mary Shelley's Frankenstein, Robert Walton openly states his reasoning behind his expedition to the north.

I may there discover the wondrous power which attracts the needle;  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.

Essentially, Robert Walton desires a few things to come out of his expedition. First, he wishes to discover the "seat of magnetism." This means that he desires to find the place on Earth which regulates the magnetism. Second, Walton wants to see a place no other man has ever seen. On top of that, not only does he want to see an unexplored area, he wishes to be the first one to set foot upon an unexplored territory. He wants to be the first one to place a footprint upon a never before touched place. Outside of that, Walton knows that his travels could result in a new path which other travelers and shippers could use.

In the end, Walton is simply seeking personal and historical renown. He wants to be known for doing/finding something which no others have ever found before.

Why is Walton going to the North Pole in Shelley's Frankenstein?

As a foil to Victor Frankenstein, Robert Walton also seeks "the country of eternal light," knowledge not yet in anyone's possession. He writes to his sister of his desire to visit what he considers "the region of beauty and delight" where the sun is visible continually, a sun that "diffuses a perpetual splendor." It is a part of the world that has never been visited before, a place where he may be the first to "tread a land never before imprinted by the foot of man." Further, Walton hopes to ascertain "the secret of the magnet," the magnetic pull which affects the seaman's compass.

Walton has studied and conditioned himself to the severe cold for six years in preparation for his great venture. Against the arguments of his sister Margaret, Walton writes,

And now, dear Margaret, do I not deserve to accomplish some great purpose?....Oh, that some encouraging voice would answer in the affirmative!

Like Victor Frankenstein, Robert Walton is obsessed with a grandiose idea, a goal of achieving what no other man has done. But, Walton, unlike Victor, is not passionate enough to pursue what he knows is impossible, nor is he obsessive enough to risk the lives of his crew members and so he fails in his mission:

The die is cast: I have consented to return if we are not destroyed. Thus are my hopes blasted by cowardice and indecision; I come back ignorant and disappointed.

In the end, Robert Walton is again like Victor Frankenstein--disappointed. But he has served as a foil to Victor, and has narrated well Victor's tale of grave disappointment.