Ferguson, the astronomer, lived by portrait painting, until his merits as a scientific man were recognized. John Dollond maintained himself as a silk weaver in Spitalfields. In the course of his studies he made great improvements in the refracting telescope; and the achromatic telescope, which he invented, gave him a high rank among the philosophers of his age. But during the greater part of his life, while he was carrying on his investigations, he continued, until the age of forty-six, to carry on his original trade. At length he confined himself entirely to making telescopes; and then he gave up his trade of a silk weaver. Winckelmann, the distinguished writer on classical antiquities and the fine arts, was the son of a shoemaker. His father endeavoured, as long as he could, to give his hoy a learned education; but becoming ill and worn-out, he had eventually to retire to the hospital. Winckelmann and his father were once accustomed to sing at night in the streets to raise fees to enable the boy to attend the grammar school. The younger Winckelmann then undertook, by hard labour, to support his father; and afterwards, by means of teaching, to keep himself at college. Every one knows how distinguished he eventually became. Samuel Richardson, while writing his novels, stuck to his trade of a bookseller. He sold his books in the front shop, while he wrote them in the back. He would not give himself up to authorship, because he loved his independence. "You know," he said to his friend Defreval, "how my business engages me. You know by what snatches of time I write, that I may not neglect that, and that I may preserve that independency which is the comfort of my life. I never sought out of myself for patrons. My own industry and God's providence have been my whole reliance. The great are not great to me unless they are good, and it is a glorious privilege that a middling man enjoys, who has preserved his independency, and can occasionally (though not stoically) tell the world what he thinks of that world, in hopes to contribute, though by his mite, to mend it."