HISTORY OF THE COMPOUND MICROSCOPE

Although spectacles existed long before, the compound microscope was the first instrument specifically designed to magnify small objects in a major way. This happened so long ago that the records do not definitively disclose who invented the instrument. Hans and Zaccharias Jansen have been given the credit by some historians, but the bulk of the evidence does NOT support this claim. What we do know is that compound microscopes existed in the 1590's and that in 1609 Galileo Galilei was using a compound microscope. Some Italian historians credit Galileo with the invention, but there is no real evidence to support this; Galileo was certainly one of the earliest users of both the telescope and compound microscope.

In 1619 Cornelius Drebbel was exhibiting a compound microscope in London, with two convex lenses. In 1625 Giovanni Faber of Bamberg first coined the term microscope. The details of most of these early compound instruments dating to before the time of Hooke, Campani and Divini, are not well documented; their constructive details, when pictured or discussed, are only derived from incomplete descriptions and poor illustrations. It is from the middle of the 17th century that good illustrations, and some actual instruments now survive. Among the earliest of these are instruments by Hooke, Divini and Campani.

In 1665 Robert Hooke published Micrographia, a collection of biological micrographs. He coined the word cell for the structures he discovered in cork bark. The construction and appearance of his compound microscope is among the earliest of which we have good documentation and good engravings. The earliest extant microscopes also date to the early to mid 17th century. Campani and Divini microscopes are from this era. From slightly later in the century there are also in existance, microscopes made by Yarwell, and a few others; some of the microscopes of this time are unsigned and so their specific origin and makers in some cases remain uncertain. Most of the few surviving instruments from the 17th century exist in museums and are valued in the 100's of thousands of dollars. Few private collectors possess (or could afford) one of these instruments. Yarwell instruments from the late 1600's are small tripod instruments similar to the Italian models in some ways. Most serious collector's earliest instruments date to the eighteenth century. Found early in the 1700's, John Marshall microscopes exist only in very exclusive collections.

Major progress in microscope design started in the early nineteenth century and culminated in the 2nd quarter of the nineteenth with the development of optics that were both achromatic and aplanatic on rigidly supported stands; as optics improved further, so did the stands themselves. The development of achromatic-aplanatic optics is arguably the most important development in the history of the microscope. In 1872 Ernst Abbe developed the wave theory of microscopical imaging which allowed all lens configurations in a microscope to be precisely calculated; there was no longer any need for any trial and error. After joining forces with Otto Schott, a glass specialist, Zeiss and Abbe were the first to create apochromatic objectives in 1886. In addition, when, upon the death of Zeiss, Abbe took over the Zeiss company in 1888 he created a very humane work program for all the Zeiss workers which served as a model for employment to this day. In 1893 August Kohler published his landmark work on optimal illumination of subjects using a microscope which optimized imaging, especially for imaging from then on through the present day.

Bausch & Lomb were the first firm to market a microscope with the stage facing the user in their sophisticated DDE model, first introduced in 1929. With front-angled binocular, the inclination joint was eliminated, though the entire microscope could be positioned horizontally for photography if desired. With the stage facing the user, access to the stage and specimens on it was much improved. It still used a mirror to reflect light from a separate source up through the stage, and was produced into the 1950s.

On the optical side, the development of phase contrast, introduced by Zernicke in the 1930s revolutionized the microscopy of subjects that have a refractive index close to that of water, making study of living cells and things like the process of mitosis in action a reality. Movies of these were both revealing and impressive. Interference contrast, developed in 1947 by Francis Smith and improved in 1952 by Georges Nomarkski, is a more expensive technique but eliminates the halos around objects seen with phase contrast. It also imparts a pseudo-3D and colored appearance to the object.

The modern microscope, with built in illumination, modular construction, controls close to the bottom of the microscope, and solid reliable adjustments did not reach a peak until the 1960's when the first complete form of the Leitz Ortholux microscopes were produced.* Further refinements of the light microscope continued into the twentieth century, and even now into the twenty first, with the relatively recent introduction of digital imaging and confocal microscopy. More recent developments included objectives with flatter and wider fields. Fixed tube lengths have recently been replaced with infinity optics which allows a single correction lens in the optical tube to correct the optical path from below, even when accessories are introduced between the objectives and the eyepiece; this reduced the cost of these accessories, which previously all required an additional corrective lens of their own.

*Although the first Ortholux dates to 1937, it did not yet include all the features that today would be considered a fully modern instrument, this did not occur until the 1960's.

COMPOUND MICROSCOPES ON THIS SITE

This site shows microscope in my collection, formerly in my collection, and selected instruments from the collections of my friends willing to share their images. The site includes compound microscopes of the 18th, 19th and 20th centuries. Some instruments in this collection date to as late as the last quarter of the 20th century. Although no compound instruments from the eighteenth century still remain in my own collection, some which were formerly in this collection are included on this website for interest. Countries of origin represented include U.S.A., Austria, China, England, France, Germany, Japan, and Poland. Most surviving antique microscopes are from the U.S.A., England, France and Germany, with a few from other countries; this fact is reflected in this collection. Currently there are about 140 compound microscopes listed on this page, with about 110 of these still in my collection. Many more are yet to be listed as time permits.

As noted above, the microscopes are listed by Date, by Country of Origin, by Maker, and by Type of microscope. In this way, if your interest is in instruments by a particular maker, or from only one country, you can find those instruments easier than if you had to search all the microscopes organized only one way.