In this one, Sir Roger has the company of a man named William Wimble, the younger brother to a baronet. This Will is adept at making devices used for hunting, fishing and trapping (May-Flys and Angle Rods) and could be an amazing business man except for one thing - he is a 'younger brother of a great family who had rather see their children starve like gentlemen, than thrive in a trade or profession that is beneath their quality.'
At the time Addison wrote this essay, elder sons of a gentleman inherited the estate while the younger were meant either for 'divinity, law, or physic' (medicine). If the younger son could not make it in these fields, he became reliant on his family. And for some reason, that was more acceptable than trade. Will Wimble, took care of his brother's game (hunting and trapping).
Addison wrote on the ridiculousness of this proud tradition when he wrote: "It is the happiness of a trading nation, like ours, that the younger sons though incapable of any liberal art or profession, may be placed in such a way of life, as may perhaps enable them to vie with best of their family: accordingly, we find several citizens that were launched into the world with narrow fortunes, rising by an honest industry to greater estates than those of their elder brothers.
We've seen it in many of the works by Austen and Bronte. Take for example, Pride and Prejudice, where the Bennetts, who were born into fortune, struggle while Mrs. Bennett's brother - Mr. Gardner, made a fortune in trade, perhaps surpassing his brother-in-law's income.
Food for thought.