In Sand: A Journey Through Science and the Imagination, geologist Michael Welland weaves together the many facets of sand – its science, its art, its music, its metaphorical power. At every scale, from grain to sand pile to vast deserts, sand is an extraordinary substance. Did you know, for instance, that the sand dunes of Morocco hum a G#? In this excerpt from the book, Michael Welland talks about the pioneering work of sand expert Ralph Bagnold.
The journey of a sand grain tumbling in the wind is a complex one, and while many of the aspects of that journey are understood, there is much, again, that is not. The foundation of what we do know, and of the research desert landscapes that continues today, is entirely the result of the pioneering work of one man (of whom we have already heard)—Ralph Bagnold. Today’s academic textbooks on sand transport often include advice along the lines of ‘for inspiration, read Bagnold (1941)’.
Bagnold’s early encounters with sand occurred after he was posted to Egypt in 1926. Shortly after his arrival in Cairo, he watched the first successful excavation of the Great Sphinx: ‘I watched the lion body of the Great Sphinx being slowly exposed from the sand that had buried it. For ages only the giant head had projected above the sand. As of old, gangs of workmen in continuous streams carried sand away in wicker baskets on their heads, supervised by the traditional taskmaster with the traditional whip, while the appointed song leader maintained the rhythm of movement’ (Sand, Wind, and War). It was never an ideal place to construct one of the world’s great monuments. Arguments about the age and meaning of the Sphinx still rage—there are limitations to the wisdom of that which, according to the Sphinx’s riddle, goes on four legs in the morning, on two legs at noon, and on three legs in the evening (the answer being humankind). However, its link with the building of the pyramids is clear, and King Khafre (or Chephren) was the likely builder. The Great Sphinx has spent most of its existence largely covered by the continuously drifting sand, with only its head, blasted and worn by that sand, protruding. The ravages suffered by the head confirm that the sand that buried the body has been its salvation, preserving it from abrasion. In spite of its role over the centuries as an inspiration for archaeologists, poets, travellers, and those who believe it was built by refugees from Atlantis, its life has largely been like that of an iceberg, demurely hiding its bulk beneath the surface.
It was not until early in the nineteenth century that serious attempts at excavating the Great Sphinx were made, but these were defeated by the enormous volumes of sand involved. Further efforts in 1858 and 1885 revealed a good part of the body and some of the surrounding structures, but these attempts were again abandoned. The Great Sphinx had to wait until 1925 and the arrival of the French archaeologist Émile Baraize for its full glory to be revealed. Removal of the vast quantities of sand required eleven years of labour.
In watching the results of natural sand movements on a staggering scale, Bagnold perhaps had an inkling of the way in which his future would be intimately driven, grain by grain, by sand. The insatiable curiosity that had blowing in the wind possessed him since childhood—from an early age he was ‘aware of an urge to see and do things new and unique, to explore the unknown or to explain the inexplicable in natural science’ (Sand, Wind, and War)—would carry him through an extraordinary diversity of accomplishments until his death in 1990 at the age of 94, still in full stride.
Bagnold was one of those larger-than-life characters, but he was also, unusually, deeply modest.