He was now nearly fifty. His life had been laborious, with an insufficient income. His friends, John Locke among the number, tried to obtain various positions for him, but failed. They recommended him for provost of King's College, but the position could not be obtained because he had not taken priest's orders.
Seemingly unappreciated, worn with his incessant brain work, his appetite failing, and unable to sleep, with neither mother nor wife to comfort him, the sensitive organization of the great man became overstrained, and mind and body were unfitted for work. It is stated that his ill health was in part consequent upon the burning of some manuscripts on optics, by a lighted candle on the table among his papers.
When he was fifty-three, the long hard road of poverty turned into a highway of plenty, through the influence of a friend. Charles Montague, an associate of Newton at the university and also in parliament, though nineteen years his junior,—intellectual affinities are uninfluenced by age,—had been made Commissioner of the Treasury, then Privy Councillor, then Chancellor of the Exchequer, and later still, Baron of Halifax.
Lord Halifax appointed Newton to be Warden of the Mint, and then Master, with an income of between six thousand and seven thousand five hundred dollars annually, which position he held for the remainder of his life. His home in London, where he kept six servants, with his brilliant niece, Miss Catherine Barton, for his companion, became a place of rest and comfort to the tired philosopher. Lord Halifax was a great admirer of Newton's niece, Miss Catherine Barton, to whom he left, at his death, a beautiful home and twenty-five thousand dollars, "as a token of the sincere love, affection, and esteem I have long had for her person, and as a small recompense for the pleasure and happiness I have had in her conversation."
The days of privation were over, and Newton had earned this rest and prosperity. Great people often came to dine with him. At one of his dinners, Newton proposed to drink, not to the health of kings and princes, but to all honest persons, to whatever country they belonged. "We are all friends," he added, "because we unanimously aim at the only object worthy of man, which is the knowledge of truth. We are also of the same religion, because, leading a simple life, we conform ourselves to what is right, and we endeavor sincerely to give to the Supreme Being that worship which, according to our feeble lights, we are persuaded will please him most."
Other honors now come to Newton. In 1703, he was elected President of the Royal Society, and was annually reëlected during the remaining twenty-five years of his life. On April 16, 1705, when he was sixty-three, Queen Anne conferred the honor of knighthood upon her most illustrious subject, Sir Isaac Newton, before a distinguished company at Cambridge University. In 1704, the year previous, his great work on optics had been published, written over twenty years before.
About this time, it seems that the great philosopher would have liked to marry Lady Norris, the widow of Sir William Norris, Baronet of Speke, and Member of Parliament. Sent to Delhi as ambassador to the Great Mogul, he died in 1702, between Mauritius and St. Helena, on his homeward passage. He was the third husband to Lady Norris, and Sir Isaac, now over sixty, desired to be the fourth, as appears from the following letter:—
"Madam,—Your ladyship's great grief at the loss of Sir William shows that if he had returned safe home, your ladyship could have been glad to have lived still with a husband, and therefore your aversion at present from marrying again can proceed from nothing else than the memory of him whom you have lost. To be always thinking on the dead, is to live a melancholy life among sepulchres, and how much grief is an enemy to your health, is very manifest by the sickness it brought when you received the first news of your widowhood. And can your ladyship resolve to spend the rest of your days in grief and sickness?
"Can you resolve to wear a widow's habit perpetually,—a habit which is less acceptable to company, a habit which will be always putting you in mind of your lost husband, and thereby promote you grief and indisposition till you leave it off? The proper remedy for all these mischiefs is a new husband, and whether your ladyship should admit of a proper remedy for such maladies, is a question which I hope will not need much time to consider of.