The period when the Krakatoa eruption occurred played a large role in establishing its fame, as such things as telegraphs and international news agencies helped people learn about it. Many people witnessed the eruption and related phenomena, and scientific research went very far in determining the causes. But there were limits on what research could accomplish because technical and theoretical understanding also had limits.

The communications technology of the time . . . ensured that the world’s more advanced peoples learned about the eruption within moments of its happening. But at the time the limited, and only slowly unfolding, geological knowledge then to hand did not give the audience an explanation of the events that was sufficient to soothe their fears . . .

Alfred Russel Wallace, the contemporary and rival of Charles Darwin, had conducted research in the area in the 1850s. His findings there contributed to his evolutionary theories but also to the development of geological theories that factor into understanding the Krakatoa eruption. In the 1850s, the idea of limited biota, where unique plants and animals developed independently, was still being widely challenged; field research and collecting helped to provide important supporting evidence. What is called the Wallace Line is a demarcation of radically different biota to its north and south, running through the southeast Asian islands including Indonesia.

The Wallace Line, however invisible and however controversial . . . does at least have the merit of being directly relevant to both the makings and the violent unmakings of Krakatoa. It may have played only a marginal role in the theory of the evolution of life. But it does play, if unwittingly, a very significant part in the much newer theory of plate tectonics, the evolution of the earth.

The author explains the causes of the great eruption are directly related to its position in a collision zone between the Australian Plate and the Asian Plate. This means that there will be another eruption at some time.

There is a subduction factory of monumental proportions to the south and east of Sumatra. It is uniquely sited around and beneath the small island that lies on the hinge-point between Sumatra and Java . . . The island is surrounded by countless small faults and zones of weakness . . .

The eruption culminated in a massive event in August 1883, but related rumblings had been felt for months, and even reported in the British press in May 1883. When the final, massive blast came, it was so “monstrous” that those who later wrote about it found it challenging to describe adequately. 51 250

The explosion itself was terrific, a monstrous thing that still attracts an endless procession of superlatives. It was the greatest detonation, the loudest sound, the most devastating volcanic event in modern recorded human history, and it killed more than thirty-six thousand people.

Winchester delves into the relationships between the Dutch-led relief efforts in the months following the eruption and the political upheavals among the island colonies’ native peoples. It seemed that everywhere in the East Indies, survivors and people peripherally affected were looking for an explanation, which often translated into someone—not Mother Nature—to blame. In the first few months following the eruption, there was a series of incidents: individual Javanese men with knives attacked Dutch traders or settlers. While these quickly died back, and not all the perpetrators were apprehended, they presaged several years of unrest, especially the 1888 Ban ten Peasants Revolt.

There had been many small rebellions in Java over the years; but what happened in Banten had a significance that transcended many of the other outbreaks of violence and hostility . . . The time also had great religious significance, as it marked a period when Islam had become fully entwined with the local political developments of the day . . .