Wilhelm (1840 - 1925) and Heinrich (1842 - 1907) Seibert began and trained alongside Ernst Gundlach and Edmund Hartnack in Germany in the second half of the 19th century. From 1867 to 1872 they worked as employees of the former until this year, and in collaboration with Georg Krafft, they bought the business from him after accumulating large debts due to mismanagement and emigrating to the USA. They manufactured a very good model of oil immersion objective which was very successful. After Heinrich's death, and after years of collaboration with Leitz, the company passed into their hands. By 1900 they had manufactured approximately 10,000 units.
Large microscope built at the end of the 19th century in perfect condition, made of gilded brass and blackened bronze with hardly any marks. This specimen was made specifically including accessories for observations with polarized light. The observation platform is graduated from 0 to 360º and is rotatable in order to align the light passing through the polarizer with the analyzer, obtaining spectacular images. It has 3 objectives (II, V and Immersion in oil) as well as 4 eyepieces, one with a micrometer and the other prepared to house the analyzer, all of them in good optical condition. Other accessories are a sub-base with diaphragm-iris and horizontal displacement, condenser, as well as different light limiters. The serial number is 8759, which places it in 1898. The box is perfectly preserved and still has the original key.
References: "Billings Microscope Collection" pag 79, fig. 148
G. Turner, "Great Age of the Microscope", pag 315, Num catálogo 394
H. Moe, "The Story of the Microscopes", pag 215-220
Links: http://www.musoptin.com/seibert_8773.html
http://www.antique-microscopes.com/photos/seibert.htm