Temple of Jupiter, Serapis, Italy, 1828.
© Science Museum / Science & Society Picture Library
'Section of the Temple of Jupiter Serapis, shewing the Successive Changes it has undergone'. Now known as the Macellum, the building serves as a method for measuring the bradyseismic phenomenon: corrosion on the columns caused by lithophagi (date mussels), indicates the different water levels over time. This led mathematician Charles Babbage (1791-1871) to conclude that the 'subsidence of the building was not sudden, or at one period only, but gradual, and by successive movements.' Illustration from Babbage's 'Observations on the Temple of Serapis at Pozzuoli near Naples', published in 1847.