Final answer:
Proctor uses a metaphor comparing his farm to a continent to express the immense responsibility he feels in managing his land.
Step-by-step explanation:
Proctor's comparison of his farm to a continent highlights the vast responsibility and boundless challenges he faces, much like those associated with exploring or governing a large expanse of land.
This metaphor suggests the enormity of his tasks and the weight of his obligations. The diverse examples provided, although varied in context, all illustrate the use of metaphor or perspective to convey deeper meanings about human experiences, such as the vastness of one's duties, the different impressions of the world shaped by mapmakers, or shifts in perspective when understanding literature or history.