On 17 November 1846, the 30-year old mechanic Carl Zeiss opened a workshop and a small store in Jena’s Neugasse No. 7. In just a few months, Zeiss, who not only had a solid theoretical basis and good practical experience, but was also well acquainted with scientists and mathematicians at the University of Jena, had already found clientele for whom he repaired scientific apparatuses and instruments or produced them according to the customer’s specifications. In addition, he offered eyeglasses, chemical scales, drawing apparatuses, telescopes, etc.
In 1847, his business success encouraged Zeiss to hire an assistant and an apprentice, and to rent two workrooms in Wagnergasse No. 34. In the summer of 1847, following the advice of his teacher, the botanist Mattias Jacob Schleiden, Zeiss devoted his attention to building a simple microscope. In September 1847, he produced the first loupe microscope.
At the beginning of the 1850’s, there was an increase in the demand for observation instruments from the Zeiss workshops, which now enjoyed a good reputation among microscopists due to their meticulous workmanship. At the time, the level of interest shown by scientists and medical professionals in compound microscopes was growing because these were the only instruments that provided the higher magnifications they wanted.
The time-consuming trial-and-error method required to build optical systems initially kept Zeiss from building such instruments, particularly as he was convinced that there must be some scientific way of determining the individual elements of the optical systems. However, the competition forced him to build compound microscopes in the traditional way from 1857 onwards.