Zeiss Microscopes

The world famous optical firm of Carl Zeiss was founded in 1846 and, until 1888, its sole product was based on microscopes. Ernst Abbe, who had been the chief scientist for the firm and responsible for the breakthroughs in design and optical formulation for the firm, formed the management organization called the Carl Zeiss Stiftung which became the owner of the firm. From that point on, Zeiss would move into all sorts of new scientific areas of optics and fine mechanics. The firm would continually make the first and strongest scientific steps into almost every area of these disciplines.

simplemkThis simple microscope was the first type produced in the Zeiss workshop in Jena. This was when he was primarily a resource for the construction of scientific tools and demonstration materials for the professors at the University of Jena. Microscopes of this time were merely high powered magnifying glasses. This model had a range of three magnifiers stored in this hardwood (usually mahogany) box and the instrument itself unscrewed for storage.

For the first 20 years of his business life, the firm made a average of 20 microscopes a year. An apprentice would work to construct each instrument from start to finish. Zeiss and his assistant, August Lober would guide their efforts from start to finish. There was no such activity as division of labor or specialty. Zeiss took great efforts to learn the skills necessary for optical work but never succeeded as well as did Lober, who was his first apprentice and who remained at Zeiss for his entire work life.

earlycmThis microscope was constructed while Abbe was working to define the formulae for microscope optics. It would take nearly five years for him to become successful. He did this to supplement his income as a young professor at the university. He had come to meet Carl Zeiss when he need some measuring devices to use as models for his students.

Once the principles were defined and taught to the workers at Zeiss. The firm was able to increase its manufacturing program 15 times over the next few years. This influenced Zeiss to offer Abbe a 1/3 partnership at a price. This payment was given to Abbe by his father in law who had been his mentor at the university and he was quickly in a position to pay it back based on his profits.

At this time the world was not complex enough to require patents since all workshops were small and local and copied the successes of others without reprisals. Abbe continued to develop other parts of the microscope and tools to test and measure the manufacturing processes. Abbe would want to market these as well to other manufacturers but Zeiss was afraid that they would be a threat to his business and so it was not done.

Abbe started the process of the apprentices working on specialties instead of learning woodworking, metalworking (brass and iron), glass grinding and assembly, polishing and lacquering. It improved output and he started to design different kinds of optics including immersion lenses which brought him considerable notoriety as did his “Abbe condenser” and drawing apparatus using prisms which were a precursor of many new products to come.

These early microscopes were crafted as almost works of art for the scientific customer. double1The customer was usually an individual for which this was a life time investment. So the exotic hardwoods and the brass fixtures and locked box were typical of all firms in this day.

This boxed set was clearly a microscope for someone who had to travel since it broke down into smaller pieces and fit into this small box. The objectives fit into a smaller cardboard box with fit into a smaller storage area at the right under the foot of the microscope.

This particular stand was manufactured in 1890 and has two serial numbers (747/1514). The first noted that it was the 747th compound microscope of 1514 microscopes made in the Zeiss workshop. Note the ivory keyhole located on the outside of the box. This was to enable the user to open and close it in subdued light since at this time they were 20 or more years from having available electricity in the workshop or the laboratory

This is the same compound stand that was in disassembled form in the illustration double2immediately above. This stand was constructed in 1870. At this point all of the microscopes made by Zeiss can be considered to be custom made since they were made to order based on an non-illustrated catalog.

The objectives are not yet in conformance with the soon to be standard of the Royal Microscope Society that was formed in England. Abbe would visit the annual meeting of this society twice in this period and this opened new markets and interests to the firm and spread the knowledge of his developments for the microscope beyond what was becoming Germany. At this point, Zeiss began to have a large number of exports. There is a story in one of the biographies of the Zeiss firm that an American scientist came to the Jena and ordered more than a hundred that he would resell in the US. He was clearly told that the firm could not fill such and order although by the end of the 1870’s, they were able to boost production to over a thousand microscopes a year.

Abbe was now developing new and improved objectives for the Zeiss microscopes and as you can see from the little box at the base of the instrument, they were still quite small in size, over the coming years, they would become increasingly complex with many elements according to his designs. The standardization of the “Royal Screw” would increase the market for the firm remarkably since the advanced Zeiss objectives would fit on any and all new microscopes.

By the early and mid-1880s, Zeiss was making a wide range of different microscopes. It ismicro25 difficult to identify all of them specifically because the model numbers would vary from catalog to catalog. The catalogs after 1880 were illustrated with beautiful woodcut pictures of the current models and so models after that time can be identified more easily.

This illustration shows the Ia stand from 1889. This was the year after the death of Carl Zeiss and the same year that Abbe announced new apochromatic objectives which were totally color corrected. These were possible due to the efforts of Otto Schott who had reacted to Abbe’s public statements that current glass technology would not permit such an improvement. Schott has sent glass samples that were better but not right for Abbe’s purposes. Schott relocated to Jena and after a lot of discussion between the partners Zeiss and Abbe and a subsidy from the Prussian government, a glass factory was constructed and Schott produced what Abbe was looking for. In fact, Schott revolutionized the glass industry and the the partnership was extremely successful.

Abbe was able to open the product line to photographic lenses, telescopes, binoculars, surveying instruments, spectacles and Zeiss would grow from 300 employees in 1888 to over a thousand in 1900 and the growth would be more spectacular in the following years.

On close inspection, this stand will show the growing sophistication of every element of the microscope under Abbe.

StandVIThis stand was designated with the Roman numeral VI and was very similar to the VII with the major difference of that it could be inclined. Most microscopes prior to 1880 used only a single lens at a time. Various rotating devices were made to accommodate 2,3 or more objectives at the same time.

Stops(such as those to the left of the base of the microscope) were used to control the light from the mirror. They were eventually replaced by diaphragms much as found in photographic lenses but the stops are often lost. In 1900, Zeiss had 15 woodworking shops building cases in the finest hardwoods for their instruments and so division of labor had been accomplished. Designs for the instruments and optics were exported or licensed around the world. Bausch and Lomb in the US were both licensees and importers. Licensing was important since imported instruments were heavily taxed before 1913 when the US instituted the income tax. Also, Zeiss would have many new staff to add and train before World War I created a different climate for business.

Zeiss innovations would continue through World War II and beyond when the firm would be split in two by the political tenor of the time.

This short explanation only covers a small period of the history of Zeiss microscopes before 1900. Many, many more instruments can be identified from samples and the hard covered books that Zeiss issued as catalogs from 1880 to 1939.