A New “Perspective Glass”: Telescopic Discoveries of Universal Uniformity

Abstract

The first telescopes were produced by Dutch spectacle makers around the turn of the seventeenth century. Three names are usually mentioned as possible inventors: Zacharias Janssen, his son Hans Janssen, and Hans Lippersheim. Legal documents drafted in Middleberg dated March 3, 1655, claim that Zacharias Janssen invented the telescope in Middleberg in the year 1590. The documents note that he produced two telescopes that were each sixteen inches long. He presented one to Prince Maurice and the other to Archduke Albert. Some seventeenth-century evidence for a later date comes from Christiaan Huygens. His Dioptrique includes sections titled “De Telescopiis” and “De Microscopiis” in which he writes that simple microscopes appeared soon after telescopes—“non multo post inventa telescopia”—and that either Hans Lippersheim or Zacharias Janssen invented the telescope in 1609.¹