Complex sentence: In the first three months of that year he made 507 pounds of nails in 47 days, wasting the least amount of nail rod in the process and earning for his master the highest daily return--the equivalent of eighty-five cents a day.
Split into simpler sentences: In the first three months of that year, he made 507 pounds of nails in 47 days, wasting the least amount of nail rod in the process. He earned the highest daily return for his master: the equivalent of eighty-five cents a day.