Alvan Clark and Sons Artists in Optics

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Clarks made the objectives for the largest refracting telescopes in the world; and the fifth of their efforts, their 40-inch lens at the Yerkes Observatory, has never been surpassed. Their optical work, which was re...