Product has been added to the basket

Squeezy does it

As geologist and science writer Nina Morgan discovers, geology can be music to your ears

kjhMany modern composers have been inspired by geological references.   In some cases geology serves as a metaphor. For example, in Harrison Birtwistle's 1986 composition, Earth Dances , the orchestra is divided into six 'strata', whose changing relationships reflect those of the Earth's geological layers and whose shifting relationships are designed to evoke the massive natural forces that shape the planet.

Picture: Henry Cadell and his squeeze box.


In others, geology provides the direct inspiration.  Peter Maxwell Davies' composition, The Yellow Cake Revue, is one example. Composed in 1980, the title refers to yellow cake uranium ore. Maxwell Davies , who lived in the Orkneys, wrote the piece as a contribution to the local campaign against proposed uranium mining on the Islands.

And sometimes geologists, perhaps unwittingly, adopt musical turns of phrases to their own uses. When Henry Moubray Cadell [1860 – 1934], a geologist with the Scottish Geology Survey from 1883 – 1888, and afterwards chairman of the Bridgeness Coal Company, devised his experimental 'squeeze box' he may not have been aware that to folk musicians, the term squeeze box immediately calls to mind a concertina.

This misunderstanding might well disappoint musicians, but in the 19th Century Cadell's squeeze box provided music to the ears of the Survey mappers working in the North-West Highlands of Scotland who were struggling to understand the complex structures and stratigraphic relationships they were observing in the field.

Experimental approach

As Cadell recalled in 1888 in a paper published the Transactions of the Royal Society of Edinburgh:

"Among most of the geologists who had of late years been engaged in investigation the structure of the North-West Highlands, and especially among those who did not concur in Murchison's explanations of the phenomena exhibited there, it was a growing belief that great overthrusts had been largely instrumental in producing the remarkable stratigraphical relations of the rock masses of that region.

"...It occurred to some of my colleagues and myself, after studying these great problems in the field, that experiments might be made to throw light on the work by seeking to imitate in the laboratory process we believed to have been in operation in our wild North-West Highlands at an ancient geological period."


Thus Cadell's  squeeze box apparatus was born. The design and construction of his experimental equipment was worthy of Blue Peter.  The squeeze box, he revealed, consisted of:

"A rectangular box 6 or 8 inches broad and 3-5 feet long. One end of the box was movable, and could be pushed in so as to compress longitudinally the strata inside." 

Recognising that the physical properties of experimental 'strata' needed to match those of the rocks he considered using a number of 'plastic' substances such as clays and waxes.  But then:

"The idea occurred to me that plaster of Paris, interstratifed or mixed with layers of sand, might satisfy the requirements of the case.  After several failures, this plan was successful."

The experimental method he described was equally simple:

"At the beginning of the experiments, the sliding end piece, which may be called the pressure board, was pushed in either by hand alone, or if the force required were considerable, with the help of a lever ... The sides could be removed at pleasure when it was desired to examine the section of distorted strata inside ...”

The drawings and photographs of the sections obtained in his experiments, he noted:

"tell their own tale, and require but little description." Nevertheless, in his paper he took 20 pages to discuss and 27 figures to illustrate the results.


Sources for this vignette include Henry Moubray Cadell: a geological and industrial innovator by John Mendum, The Edinburgh Geologist, issue 48, 2010, pp. 5-14; Experimental researches in Mountain-Building by H.M. Cadell, Trans. Roy. Soc Edin., 1888, vol. 35, pp. 337 – 357; information about Birtwistle comes from the website and about Maxwell Davies from

* Nina Morgan is a geologist and science writer based near Oxford.  Her latest book, The Geology of Oxford Gravestones, is available via