# Hooke's oolite

52 Things You Should Know About Rock Physics came out last week. For the first, and possibly the last, time a Fellow of the Royal Society — the most exclusive science club in the UK — drew the picture on the cover. The 353-year-old drawing was made by none other than Robert Hooke

The title page from Micrographia, and part of the dedication to Charles II. You can browse the entire book at archive.org.

The drawing, or rather the engraving that was made from it, appears on page 92 of Micrographia, Hooke's groundbreaking 1665 work on microscopy. In between discovering and publishing his eponymous law of elasticity (which Evan wrote about in connection with Lamé's $$\lambda$$), he drew and wrote about his observations of a huge range of natural specimens under the microscope. It was the first time anyone had recorded such things, and it was years before its accuracy and detail were surpassed. The book established the science of microscopy, and also coined the word cell, in its biological context.

Sadly, the original drawing, along with every other drawing but one from the volume, was lost in the Great Fire of London, 350 years ago almost to the day.

### Ketton stone

The drawing on the cover of the new book is of the fractured surface of Ketton stone, a Middle Jurassic oolite from central England. Hooke's own description of the rock, which he mistakenly called Kettering Stone, is rather wonderful:

I wonder if anyone else has ever described oolite as looking like the ovary of a herring?

These thoughtful descriptions, revealing a profundly learned scientist, hint at why Hooke has been called 'England's Leonardo'. It seems likely that he came by the stone via his interest in architecture, and especially through his friendsip with Christopher Wren. By 1663, when it's likely Hooke made his observations, Wren had used the stone in the façades of several Cambridge colleges, including the chapels of Pembroke and Emmanuel, and the Wren Library at Trinity (shown here). Masons call porous, isotropic rock like Ketton stone 'freestone', because they can carve it freely to make ornate designs. Rock physics in action!

You can read more about Hooke's oolite, and the geological significance of his observations, in an excellent short paper by material scientist Derek Hull (1997). It includes these images of Ketton stone, for comparison with Hooke's drawing:

Reflected light photomicrograph (left) and backscatter scanning electron microscope image (right) of Ketton Stone. Adapted from figures 2 and 3 of Hull (1997). Images are © Royal Society and used in accordance with their terms.

I love that this book, which is mostly about the elastic behaviour of rocks, bears an illustration by the man that first described elasticity. Better still, the illustration is of a fractured rock — making it the perfect preface.

References

Hall, M & E Bianco (eds.) (2016). 52 Things You Should Know About Rock Physics. Nova Scotia: Agile Libre, 134 pp.

Hooke, R (1665). Micrographia: or some Physiological Descriptions of Minute Bodies made by Magnifying Glasses, pp. 93–100. The Royal Society, London, 1665.

Hull, D (1997). Robert Hooke: A fractographic study of Kettering-stone. Notes and Records of the Royal Society of London 51, p 45-55. DOI: 10.1098/rsnr.1997.0005.

1 Comment

### Matt Hall

Matt is a geoscientist in Nova Scotia, Canada. Founder of Agile Scientific, co-founder of The HUB South Shore. Matt is into geology, geophysics, and machine learning.

Doing your best work requires placing yourself in the right environment. For me, I need to be in an uncluttered space, free from major distractions, yet close enough to interactions to avoid prolonged isolation. I also believe in surrounding yourself with the energetic and inspired people, if you can afford such a luxury.

### The model workspace

My wife an I are re-doing our office at home. Currently mulling over design ideas, but websites and catalogs only take me so far. I find they fall short of giving me the actual look and feel of a future space. To cope, I have built a model using SketchUp, catering to my geeky need for spatial visualization. It took me 35 minutes to build the framework using SketchUp: the walls, doors and closets and windows. Now, it's taking us much longer to design and build the workspace inside it. I was under the impression that, just as in geoscience, we need models for making detailed descisions. But perhaps, this model is complicating or delaying us getting started. Or maybe we are just being picky. Refined tastes.

This is a completely to-scale drafting of my new office. It is missing some furniture, but the main workspace is shown on the left wall; a large, expansive desk to house (up to) two monitors, two chairs, and two laptops. The wide window sill will be fitted with bench cushions for reading. Since we want a built-in look, it makes sense construct a digital model to see how the components line up with other features in the space.

### More than one place to work

So much of what we do in geoscience is centered around effectively displaying information, so it helps to feel fresh and inspired by the environment beyond the desktop. Where we work affects how we work. Matt and I have that luxury of defining our professional spaces, and we are flexible and portable enough to work in a number of settings. I like this.

There is a second place to go to when I want to get out of the confines of my condo. I spend about 30 hours a month at a co-working space downtown. The change in scenery is invigorating. I can breathe the same air as like-minded entrepreneurs, freelancers, and sprouters of companies. I can plug into large monitors, duck into a private room for a conference call, hold a meeting, or collaborate with others. Part of what makes an office is the technology, the furniture, the lighting, which is important. The other part of a workspace is your relationship and interaction to other people and places; a sense of community.

What does your best work space look like? Are you working there now?