The earliest known working telescopes appeared in 1608 and are credited to Hans Lippershey. Among many others who claim to do so were Zacharias Janssen, spectacle-makers in Middelburg, and Jacob Metius of Alkmaar. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. 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 extremely large and unwieldy Keplerian telescopes with compound eyepieces. Hans Lippershey is the earliest person documented to have applied for a patent for the device.
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