Creators of Petrographic Microscope

Documentation of the progressive evolution in microscope design for the additional prominent makers of petrographic microscopes and accessories can be found in their trade catalogs, where distinctive features can be noted for each manufacturer. Other publications record the instruments in a variety of scientific and museum collections, providing valuable details of design and construction for the majority of the significant companies, example, Purtle, Turner, Brown, and Holland.

Alternatively, standard textbook references on optical crystallography offer detailed diagrams and descriptions of petrographic microscopes made by a lot of the early firms. Finally, a number of museums and public institutions house collections of mineralogical instruments that give invaluable information, example, the Harvard University Collection of Historic Scientific Instruments like the Denver Museum of Nature and Science for example and the Colorado School of Mines Geology Museum. Turner as well provides a list of museums worldwide which exhibit or archive microscopes. Other sources of information record the histories of individual companies, while Bracegirdle provides precise information that correlates instrument serial numbers to manufacture dates for numerous companies.

Though general design features are consistent among the manufacturers for a given era, each instruments of the firm yet featured varying details of construction that distinguished their product from that of their competitors. Though, because microscope manufacturers liberally copied the innovations of their competitors, new ideas frequently rapidly became standard throughout the industry. Some factors can make the determination of manufacturer rather subjective for example is some firms did not sign their instruments or accessories, requiring an identification of provenance based solely on design features.