The works of Robert Hooke are well preserved at St John’s College Library with the library holding copies of 17th-century publications of Hooke’s work on microscopy, observations of comets, and the proposition of his eponymous law of elasticity.

Robert Hooke (1635-1703) was renowned in his day for being an early member of the Royal Society – for which he was, at various points of time, curator of experiments, member of the council, and secretary – and for being a leading figure in 17^th-century science, working closely with the likes of Christopher Wren, Robert Boyle, and Isaac Newton. Over time his reputation slipped somewhat, and there was a tendency to consider him, in the words of biographer Lisa Jardine, “the man who almost made great discoveries, now tied to the names and enduring fame of others”. More recently his character and the range of his contributions have attracted some interest.

Hooke made strides in a great number of fields beyond the microscopy, astronomy and elasticity previously mentioned; these include

• building vacuum pumps with Robert Boyle
• building Gregorian telescopes to observe Mars’ and Jupiter’s rotations
• establishing a hypothesis that planetary movements were linked to gravity
• publishing works on refraction
• suggesting that matter expands when heated, and that air is made up of particles
• making the first modern plan-form map of London
• teaching Geometry as Professor of Gresham College, London

Micrographia

First published in 1665, Hooke’s book includes 38 plates of microscopic drawings and engravings which he was able to produce by consulting his compound microscope. This microscope produced a severely distorted view of its object, yet Hooke’s drawings do not share these distortions; Hooke built up each complete image, such as that of the fly below, by examining each section in detail and working out an accurate depiction without distortion.

Micrographia is not the earliest example of microscopic drawings being mass-produced in this way, but it is the first of its kind in that it is entirely devoted to the microscopy and accompanying commentary.

Also notable in this text – which made Hooke’s name – is his coining of the use of the word ‘cell’ in a biological context. When describing the structure of cork tissue Hooke uses ‘cell’ to liken the structure to honeycomb pores.

Although Micrographia was first published in 1665, its immediate popularity demanded reprints. St John’s copy is a 1667 printing from the Royal Society’s printer, John Martyn. Micrographia was one of the Royal Society’s earliest publications, and its success helped to establish the Society’s general reputation beyond the scientific community.

Philosophical Tracts of the Royal Society (1678)

Later publications by the Royal Society include general surmises of recent lectures and research tracts. By 1678, when Hooke was the Society’s Secretary, collections of this sort by the Society were increasing in frequency. In this particular volume, of the ten lectures and collections, three scientific publications are tied to Hooke: a collection on mechanics and lamps, a second on observations of comets, and a third on springs and elasticity. St John’s copy of these tracts was also published by John Martyn, Royal Society printer.

Lamps and Mechanics

Hooke’s work on the mechanical improvements of lamps seemingly combines his early architectural training with his scientific vocation. Often with his inventions, he would be behind both the design and the physical construction of the scientific instruments including, as described in this tract, mechanical lamps, built with a focus on making the most efficient use of the flame’s heat energy.

This particular tract on mechanics was closely linked, as Hooke notes in the opening paragraph, to his earlier work on ‘Fire and Flame’. Hooke combined his work on the nature of gases and air – analysing different parts of the flame to distinguish where heat is strongest, for example – with mechanics in his designs, as shown below in the diagrams.

Comets

Hooke’s lectures and observations are published in this collection alongside correspondence with other scientists working on the same thing: including Edmond Halley, who would, in 1705, make his name by calculating the regular orbit of Halley’s Comet.

Hooke’s work on comets, and indeed optics, contributed to his subsequent analysis of the curvilinear motion of celestial bodies. These findings led to Hooke reaching a level of understanding that there must be a gravitational pull between objects in the solar system, before Isaac Newton’s seminal work on the subject. Indeed, some historians such as Domenico Bertolini Meli speculate that “Hooke prodded Newton into action, and provided him with a fruitful framework for tackling the problem of orbital motion.”

Springs

While several of Hooke’s scientific contributions may have been overlooked at times, the law of elasticity which bears his name has ensured that he has not ever been totally forgotten. ‘Hooke’s Law’ states that the force (F) needed to extend or compress a spring is directly proportional to the distance (X) required to fully compress or extend the spring; hence F =kX.

In the publication preserved in this collection of Royal Society proceedings, Hooke uncovers the solution to an anagram he published two years earlier. His anagram – c e i i n o s s t t u u – resolves to the Latin phrase ut tension, sic vis, meaning ‘as the extension, so the force’. In this own words:

“The Power of any Spring is in the same proportion with the Tension thereof: That is, if one power stretch or bend is one space, two will bend it two, and three will bend it three, and so forward.”

References

Doherty, Meghan C., ‘Discovering the “true form:” Hooke’s “Micrographia” and the visual vocabulary of engraved portraits’, Notes and records of the Royal Society of London, Volume 66, No. 3 (20 September 2012), 211-234

Jardine, Lisa, The Curious Life of Robert Hooke: The Man who Measured London, (London: Harper Perennial, 2004)

Jourdain, Philip E. B., ‘Robert Hooke as a precursor of Newton’, The Monist, Volume 23, No. 3 (July 1913), 353-384

Meli, Domenico Bertoloni, ‘Who Is Afraid of Centrifugal Force?’, Early Science and Medicine, Volume 10, No. 4 (2005), 535-543