In Mary Shelley's novel "Frankenstein," the comparison between Robert Walton and Victor Frankenstein revolves around their mutual sense of adventure and unquenchable desire for knowledge. Robert and Victor possess the same thirst for knowledge, and the only thing that saves Robert's life is Victor's terrible fate.
Robert and Victor are alike because they become obsessed with something that preoccupies their lives and puts them at risk. In an article on the University of Pennsylvania's website, it's noted that "Walton's ambition to make his mark as a scientist, then, is very large and of potentially enormous utility." This ambition is no different from than that of Victor. Both men sought power and knowledge and both men would go to the ends of the earth to find it.
Walton was ready to die in the Arctic to satisfy his craving to solve mysteries of the universe. When he writes, "I may there discover the wondrous power which attracts the needle; and may regulate a thousand celestial observations," he's illustrating his similarity to Victor who wrote something comparable when he said, "I had worked hard for nearly two years, for the sole purpose of infusing life into an inanimate body. For this I had deprived myself of rest and health, I had desired it with an ardor that far exceeded moderation."