You could say Marvin Bolt takes the long view.

He’s on a worldwide quest to track down and catalog the oldest telescopes known to man, dating to the early 1600s and the days of Galileo.

“You’d think after 400 years, people would know where they are,” said Bolt, the science and technology curator at the Corning Museum of Glass.

So far, he has traced relics to private collections and museums throughout Europe, where the hand-held instruments first opened astronomers’ eyes to moons and planets and served as military surveillance tools.

The hunt has taken him to 21 countries, including China, Portugal, Estonia and the Vatican.

“We have to make a systematic study of actual objects: Where are they? How many are there and what can you actually see through them?”

Backed by grants from the National Endowment for the Humanities and the National Science Foundation, Bolt has since cataloged more than 1,000 telescopes made before 1750, when the addition of a second piece of glass to the lens improved the quality and led to a production surge.