Sand witnessed the completion of Chopin's greatest masterpiece, the cycle of 24 Preludes. He had to struggle with a poor rental piano and became unhappy and fell ill, but received little help from local doctors. Later Chopin enjoyed a better environment at Sand's estate in Nohant. There his creativity flourished during the summers of 1839 until 1843. At that time Chopin composed many important works. However, Chopin and Sand were not a good match, and eventually their differences prevailed. Sand was a pipe smoker and a flamboyant party goer. Chopin suffered from bronchial asthma and tuberculosis and needed a quiet solitude for his music.