Three Stones Make a Wall: The Story of Archaeology
Eric H Cline
Princeton University Press
458pp, 57 drawings by Glynis Fawkes and two maps
Hardback, £30/$35

Archaeology is a modern discipline, a creation of the Enlightenment and the Age of Reason. Yet speculation and supposition are the necessary evils of archaeological interpretation. 'One stone is a stone,' goes the archaeologists' ungrammatical axiom, 'Two stones is a feature. Three stones is a wall. Four stones is a building. Fives stones is a palace. Six stones is a palace built by aliens.'

Eric H Cline, the eminent American archaeologist, has more than 30 years' field experience in the Eastern Mediterranean, and a deep understanding of archaeological history. Three Stones Make A Wall is a superb one-volume history of the discipline – in its sweep and expertise, a modern heir to CW Ceram's Gods, Graves and Scholars, published in 1949.

Cline's approach is essentially chronological, from the origins of modern archaeology – in Emmanuel Maurice de Lorraine's discovery, in 1752, of 300 papyrus scrolls at Herculaneum – to the present and future, with the looting of antiquities amid war in the Middle East, and the remarkable progress of the archaeologist's technical arsenal. Each phase of the story, from Pompeii to Troy, from Troy to Egypt and Mesopotamia, from Mesopotamia to Meso- america, is narrated from the first strike of the trowel on ground to the current state of excavations. At Herculaneum, archaeologists now use CT scans, X-rays, laser imaging and DNA analysis. They record and document in the field 'directly onto iPads with cloud-based storage for the data'. At Rome, the Mussolini-era reconstruction of the Ara Pacis altar site was renovated in 2006, but doubts persist as to its accuracy. Similar doubts attend Yigal Yadin's interpretations of his finds at Masada in Israel. A 'simple reading of the data' leads to necessary speculation, because data is never complete.

Mixed in with the legendary personalities and sites of the great age of archaeology are Cline's personal experiences. On his first dig, he is lowered into a well in the Stoa at Athens. In 2008, searching for reasons why a Canaanite house at Megiddo in Israel might have been destroyed, he finds modern bullet casings. Back at his base, George Washington University, Cline consults an adjunct instructor who also works at the Bureau of Alcohol, Tobacco and Firearms. The instructor matches the bullet casings to a Czech machine-gun from the 1940s.

A second thread in the story is technical. Short chapters explain how the techniques of fieldwork developed. Flinders Petrie pioneered vertical excavation. Mortimer Wheeler invented a method of excavating blocks five metres square, with a one-metre 'balk' in between. The result, which resembles a giant, 'rectangular ice-cube tray', allows archaeologists to keep track of the site's stratigraphy, the stacking of historical layers in the soil.

Stratigraphy is recorded with a Harris matrix, first as a rough field sketch, later as a detailed grid. William Libby's legacy, Carbon-14 dating, is applied to organic materials. Thermoluminescence can determine the age of a clay potsherd, by measuring electromagnetic or ionizing radiation. The newest method, rehydroxylation, measures the amount of water in a piece of pottery. When researchers at Canterbury tested a medieval brick with rehydroxylation, they were baffled to find the brick was only 66 years old. Then they realised that the brick came from an area of Canterbury that had been bombed during the Second World War. A fire had 'reset' the brick's water content back to zero.

Cline follows his story from the first hominids to 'future archaeology'. If we undergo a Pompeii-style disaster, what will future hominids make of the 'ubiquitous blobs of metal, plastic, glass and circuitry' held by almost every skeleton? Interpretation will always be essential to archaeology, and Three Stones Make a Wall is a masterpiece of historical interpretation.
Dominic Green