Refracting telescope
Refractors were the earliest type of optical telescope. The first practical refracting telescopes appeared in the Netherlands about 1608, and were credited to three individuals, Hans Lippershey and Zacharias Janssen, spectacle-makers in Middelburg, and Jacob Metius of Alkmaar. Galileo Galilei, happening to be in Venice in about the month of May 1609, heard of the invention and constructed a version of his own. Galileo then communicated the details of his invention to the public, and presented the instrument itself to the Doge Leonardo Donato, sitting in full council.
Telemeter
In 1781 Georg Friedrich Brander invented the coincidence telemeter. Two mirrors set a distance apart horizontally and forming two images in the same eyepiece. This rangefinder does not require a measuring rod at the target and could perhaps be considered the first true telemeter. In 1790 Jesse Ramsden invented a half-image range finder. In 1899 Carl Pulfrich at Carl Zeiss AG invented the stereo telemeter.