Final answer:
The author uses the Mont Blanc example to illustrate the concept of scale and to highlight that even monumental tasks or changes could have surprisingly small effects when measured against a wider or larger context.
Step-by-step explanation:
The author's point in presenting the example of flattening Mont Blanc and the minimal impact it would have on raising the level of France is to illustrate the concept of scale. In literature, this illustration is an effective way to talk about immense sizes and impacts in more tangible terms. The Mont Blanc example is probably a metaphor and it serves to emphasize that even enormous tasks or changes may have a surprisingly small overall effect when compared against the vastness of other entities or conditions. In other words, it's a demonstration of the relative impact of isolated actions or events within a larger context.
Learn more about Concept of Scale