them. Voltaire was a favorite with those of his time, more especially with Madame du Châtelet, who went so far as to place her castle at Cirey at his disposal. She was a very clever woman, wrote books on philosophy, and at the same time she was extremely frivolous—just the sort of combination Voltaire loved. At Cirey he interested himself in refurnishing the house and in gardening. He set up a laboratory and experimented in physics; he busied himself with iron-founding; he studied astronomy and philosophy with his hostess, made love to her, quarreled with her over trifles, for she had a very hot temper; and all the while kept on producing an almost incredible amount of writings. Cirey became his home and headquarters till Madame du Châtelet died in 1749. During this period he came again into Court favor, wrote a play which was performed before the King, and was made Historiographer and Gentleman of the Chamber.
One of the most curious and interesting incidents in Voltaire's life was his friendship with Frederick the Great of Prussia. After the exchange of many enthusiastic and ridiculously complimentary letters, they met first in 1740, and subsequently Voltaire went over to Berlin on a diplomatic mission. But it was not till 1751 that he went and stayed for any length of time with his royal friend. Half the world watched the meetings of the two most prominent men of the day. They were very different, and this made their intimacy all the more surprising. The very slender
