What evidence is there in Letter I in Frankensstein that Walton has a highly developed imagination?
We need look no further than Walton's description of how he imagines the North Pole to be in his mind's eye. Note the way in which his imagination causes him to ignore traditional and much more realistic views that the North Pole is a place defined by "frost and desolation" alone. It causes him to have a rather imaginative and intensely Romantic idea of what he will find when he finally penetrates the North Pole to its heart:
I try in vain to be persuaded that the pole is the seat of frost and desolation; it ever presents itself to my imagination as the region of beauty and delight. There, Margaret, the sun is for ever visible; its broad disk just skirting the horizon, and diffusing a perpetual splendour. There--for with your leave, my sister, I will put some trust in preceding navigators--there snow and frost are banished; and, sailing over a calm sea, we may be wafted to a land surpassing in wonders and in beauty every region hitherto discovered on the habitable globe. Its productions and features may be without example, as the phenomena of the heavenly bodies undoubtedly are in those undiscovered solitudes. What may not be expected in a country of eternal light?
The way in which he describes the sun as a "broad disk just skirting the horizon" with its "perpetual splendour" clearly speaks of his Romantic ideas and give a powerful sign of how strong the imagination is in terms of what is driving him to embark upon this quest. He imagines a fairytale world of wonders that have not yet been found on this planet and describes it as a country of "eternal night." The imagination is shown therefore to be key in the way that Walton contemplates what he will find at the end of his journey. It also helps us to understand the powerful ambition that drives him.