History of Telescopes

The earliest known working telescopes appeared in 1608 and are credited to Hans Lippershey. Among many others who claimed to have made the discovery were Zacharias Janssen, spectacle-maker in Middelburg, and Jacob Metius of Alkmaar. Galileo used this design the following year. In 1611, Johannes Kepler described how a telescope could be made with a convex objective and eyepiece lens and by 1655 astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces. Hans Lippershey is the earliest person documented to have applied for a patent for the device. Isaac Newton is credited with building the first "practical" reflector in 1668. Writings by John Dee and Thomas Digges in England in 1570 and 1571, respectively ascribe the use of both reflecting and refracting telescopes to Thomas' father Leonard Digges, and it is independently confirmed by a report by William Bourne in approximately 1580. They may have been experimental devices and were never widely reported or reproduced.