In Mary Shelley's Frankenstein, Walton and Frankenstein have a great deal in common, as they discover at the story's end. One of their commonalities is a desire to help the world in an unprecedented way.
In writing letters to Mrs. Margaret Saville (his sister), the reader learns of Walton's desire to observe parts of the world he has never before seen, but more so the regions of the North Pole ("a country of eternal light") that have never been visited by anyone ever before. He wants to "tread a land never before imprinted by the foot of man." He acknowledges that he will see beautiful things. He admits that no amount of talking to himself can dispel the daydreams he has had. He is also aware that his journey may confront him with danger or even death, but that the anticipation of his potential experiences and discoveries outweigh those concerns.
Walton goes on to write:
...you cannot contest the inestimable benefit which I shall confer on all mankind, to the last generation, by discovering a passage near the pole to those countries, to reach which at present so many months are requisite; or by ascertaining the secret of the magnet, which, if at all possible, can only be effected by an undertaking such as mine.
Walton's dream—like countless explorers before him (Magellan, Columbus, etc.)—is to find a way over the North Pole to enable shorter travel to places on the other side of the globe that now take months on end to reach by sea. He also wants to discover the secret of magnetism, something unknown at this time.
Like Frankenstein, Walton allows his dream to become an obsession. He ultimately puts the lives of the members of his crew at risk. When confronted by the potential consequences of his actions, it is interesting to look also to Victor Frankenstein to see how these men's choices are similar and how vastly their actions differ.