Thomas Grubb: Grubb ParsonsTelescope Company

I n the history of modern science there are likely no more underappreciated names than those of Thomas or Howard Grubb. Despite their company's 150-year history of producing many of the world's largest research instruments, few remember them. Even William Parsons, the Grubbs' neighbor and future business partner, became better known for the creation of a single telescope, a 72-inch monstrosity that was all but imobile.

The Lick Observatory 36" scope and the Yerkes 40" refractor were each, at their times of completion, the largest refracting telescopes in the world, a distinction the Clarks accomplished five times over the 87 year course of their company's life. The Lick telescope remains the world's third largest refractor. The Yerkes is still the largest, though it might be more accurate to call it the world's largest successful refractor.

In 1900, the Great Paris Exhibition Telescope. In 1900, the Great Paris Exhibition Telescope was unveiled at that year's Paris Universal Exhibition. It had interchangeable lenses for visual and photographic uses, but its main primary lens diameter was 49.2 inches with a 187 foot focal length. The project was headed by François Deloncle (1856–1922) and took 8 years to build. It was made primarily for exhibition purposes and was so heavy, long and awkwardly mounted that pointing the scope was nearly impossible. Soon after the exhibition it was dismantled. All that remains are the lenses, which are still kept at the Paris observatory.