Living History with Solar Microscopes


A giant image of a flea projected using an eighteenth-century solar microscope.

What insights that can be gained through reenactments using historic instruments? One example can be found in Peter Heering’s use of solar microscopes. These sun-lit microscopes were built to see small objects magnified by projecting images of specimens on a wall. This pastime fascinated eighteenth century elites. Heering wondered why these solar microscopes were so popular during the 18th century yet dismissed in the 19th century as mere “toys.” If they were so inferior, why were they so popular with the most educated social class. Were they really that inferior? Heering found that when he actually used an original eighteenth-century solar microscope, lent by the Deutsches Museum in Munich, to project images of specimens, he was astonished by the brilliance of the sunlit image. The solar microscope images were much brighter than images illuminated by modern artificial light!

So why had 19th century scientists distained these simple but effective instruments as producing only shadowy, blurry images? Heering had the opportunity to try solar microscopes by several different makers and found that the image quality and ease of use varied considerably. He found that to exhibit these properly, one needed both a well-constructed instrument and a perceptive, skilled demonstrator (to adjust the light as the sun moved, for example). So, it is not enough to look at history through the study of “residual material traces such as books, images or instruments in showcases.” Embodied skills – such as setting up a solar microscope – can also inform our historical understandings.

This experiment with the solar microscope display tells us something about the development of laboratory science in the 19th century. Laboratories tend to exclude the casual observer. An ordinary person might have an inexpensive solar microscope but not the more “modern” lab instrument. The expensive equipment in the lab may not necessarily do a better job, but it does make the work of science more special and exclusive. In what other ways has the development of science as a profession excluded the observations of ordinary people? The solar microscope is one example of how being historically informed can change our perception of what science is and how it might be done.

One way that the scientific community has become more inclusive is through the recruitment of citizen scientists. Projects from counting birds to studying cancer ask volunteers to get out in the field or identify patterns to contribute to scientific understanding. The solar microscope is an early example of non-specialists being involved in science, delighting in wonder at the natural world.

[1] Peter Heering, “The Enlightened Microscope: Re-Enactment and Analysis of Projections with Eighteenth-Century Solar Microscopes,”  British Journal for the History of Science, Vol. 41, No. 3 (Sep., 2008), 358.