As to Caroline Herschel as a helper and sustainer of her illustrious brother, too much cannot be said. "In the days when he gave up a lucrative career that he might devote himself to astronomy, it was owing to her thrift and care that he was not harassed by the rankling vexations of money matters. She had been his helper and assistant when he was a leading musician; she became his helper and assistant when he gave himself up to astronomy. By sheer force of will and devoted affection she learned enough of mathematics and of methods of calculation, which to those unlearned seem mysteries, to be able to commit to writing his researches. She became his assistant in the workshop; she helped him to grind and polish his mirrors; she stood beside his telescope in the nights of midwinter, to write down his observations when the very ink was frozen in the bottle. She kept him alive by her care; thinking nothing of herself, she lived for him. She loved him and believed in him, and helped him with all her heart and with all her strength. She might have become a distinguished woman on her own account, for with the seven-foot Newtonian sweeper given her by her brother she discovered eight comets first and last. But the pleasure of seeking and finding for herself was scarcely tested. She 'minded the heavens' for her brother; she worked for him, not for herself, and the unconscious self-denial with which she gave up 'her own pleasure in the use of her sweeper' is not the least beautiful picture in her life."[249] While recounting the achievements of women who directly or indirectly contributed to our knowledge of the earth and what it contains we cannot forget what the world owes to the gracious and glorious Isabella of Castile. For it is to her probably as much as to Columbus that a new continent was discovered at the close of the fifteenth century. For, while the doctors of Salamanca--most of whom were what Galileo called "paper philosophers," men who fancied that a correct knowledge of the physical universe was to be obtained by a collation of ancient texts--were denouncing the great navigator as an idle dreamer, and quoting the ill-founded notions of Pliny and Aristotle to prove the impossibility of his carrying out his project, Isabella was quietly revolving in her own mind the reasons which Columbus had adduced in favor of his great enterprise. Having satisfied herself that his views were sufficiently probable to justify action, she was prepared to make any sacrifices to have his plans executed. The result of her decision is but another illustration of the value of woman's quick intuition, as against the slow reasoning processes of philosophers and men of science.