Who incorrectly believed life did not exist below 300 fathoms

I'm pretty sure it's c. extremely gradual but not 100% sure though.

Answer cumulus clouds;

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!