What are two main reasons the narrator of the first part of Frankenstein gives for why he is adventuring into the frozen north?

Robert Walton is attempting to reach the North Pole and he gives at least three reasons for doing so. He is curious to see a part of the world never seen by others, he hopes his discovery will benefit mankind, and he wants to gain glory for his discovery.

In a letter to his sister, Walton writes, "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." This desire to gain knowledge and explore untraveled land mirrors Victor Frankenstein's desire for knowledge and his unprecedented creation of human life. 

Walton goes on to say that this discovery will have an "inestimible benefit" for "all mankind." Victor Frankenstein also believed that his scientific discoveries will benefit humanity as his goal is to "banish disease from the human frame, and render man invulnerable to any but a violent death!"

Finally, Walton asks his sister, "do I not deserve to accomplish some great purpose? [...] I preferred glory to every enticement that wealth placed in my path." Similarly, Victor Frankenstein states, "Wealth was an inferior object; but what glory would attend the discovery."

Interestingly, both Walton and Frankenstein are traveling North, Walton to gain knowledge and fame, and Frankenstein to destroy that which he hoped would bring him the same.