A microscope owned by Charles Darwin that was passed down through his family for almost 200 years is expected to sell for up to £350,000 when it goes up for auction in December. The scientific instrument — originally gifted to Charles’ son, Leonard — was designed by the English microscope maker Charles Gould for the firm Cary in 1825. It is one of six known surviving microscopes associated with the British naturalist, who is best known for his contributions to our understanding of evolution.