As a man of inquiring mind, interested in cause and effect, and in philosophy, science, and literature, he formed one of the great libraries of his age, which was installed in the Louvre, where he maintained a second residence. The library’s rooms were paneled in carved and decorated cypress, stained-glass windows were screened by iron wire against “birds and other beasts,” and a silver lamp was kept burning all night so that the King could read at any time.