How had Robert Hooke’s engravings attained detail beyond the apparent powers of his microscope? Professor Brian J Ford investigated to solve the mystery…
Half a century ago I took some historic micrographs that nobody had ever done before: the view of specimens as seen through Robert Hooke’s microscope in the 1600s. I included a micrograph of cork, matching Hooke’s own drawing from 1663, in my book The Revealing Lens, published in 1973. A problem soon arose – you couldn’t see what Hooke had portrayed by looking through his compound microscope. The published engravings were rich with intricate details that his instrument could never reveal.
Hooke’s images were originally published by the Royal Society in Micrographia, a large volume that appeared in 1665. Hidden in the un-numbered pages of the Preface, I found the answer – Robert Hooke had used a single lensed microscope for his detailed observations.
Indeed, I later showed that the pioneering microscopist Antoni van Leeuwenhoek had been inspired by Hooke’s book, and Leeuwenhoek made his microscopes according to the design Hooke included in Micrographia.
Compound microscopes tend to magnify aberrations more than images, and a simple microscope comprised of just one tiny biconvex lens can give startlingly clear images at magnifications of several hundred. I have been acquiring a library of images that directly relate Hooke’s engravings to identical specimens imaged with single lenses, or modern microscopes, in order to demonstrate just how accurate were his observations.
It is a complex and delicate operation. Single lenses (as Hooke warned his readers) are hard to use and many other microscopists have failed to obtain useful results. And of course, specimens rarely match the precise appearance of those Hooke had studied. Photoshop allows us to reposition appendages, or adjust the positions of specimens, to match what Hooke had observed. The results re-create the view that the world’s first microscopist could have seen. They open a new window on the history of science, and reveal for the first time just how diligent, how precise, and how meticulous were the first pioneers of modern science.
