Optical telescope
The telescope is more a discovery of optical craftsmen than an invention of a scientist. The lens and the properties of refracting and reflecting light had been known since antiquity and theory on how they worked were developed by ancient Greek philosophers, preserved and expanded on in the medieval Islamic world, and had reached a significantly advanced state by the time of the telescope's invention in early modern Europe. But the most significant step cited in the invention of the telescope was the development of lens manufacture for spectacles, first in Venice and Florence in the thirteenth century, and later in the spectacle making centers in both the Netherlands and Germany. It is in the Netherlands in 1608 where the first recorded optical telescopes (refracting telescopes) appeared. The invention is credited to the spectacle makers Hans Lippershey and Zacharias Janssen in Middelburg, and the instrument-maker and optician Jacob Metius of Alkmaar.
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.