During the last year of travel restrictions and limited access to libraries and archives, researchers lucky enough to continue doing their work have been forced to resort to digitalised sources, probably more than ever before. Starting to work on a new research topic and confronting online repositories with thousands of pages of old journals and massive 19th century volumes, I have been constantly reminded of the very importance of knowing what you are searching for and how to name it. Because not only they did things differently in the past – they also had different names for them. So if one is looking for sediment in the printed sources of the 19th century, you’d better know what exactly you are looking for. “Sediment” will not take you too far. Instead, navigating among a flow of pebbles, cobbles, limes, and silt, one needs to slowly master the vocabulary of sedimentary rocks. Excavating the past, finding the right seam to start digging, is often to start with a matter of language and vocabulary.
Knowing the right keywords is just the beginning. “In no other science does the problem of terminology present so many difficulties as in geology”, wrote in 1922 a PhD student who was to become a renowned geologist, Chester K. Wentworth. Five years earlier he had started studying how pebbles and cobbles were shaped by running water, and in doing so he noticed the loose usage of terminology that characterised the work of geologists. Not every anglo-speaking researcher meant the same when saying pebble. Terminology was being redefined, and old words were adopting new senses. In the resulting confusion, researchers like Wentworth, among others around these years, saw the need of agreeing on a careful, international definition of these terms, and standardising its usage. By 1920, Wentworth started collecting definitions of sedimentary rock terms from encyclopaedias, dictionaries, and glossaries, some from the first decades of the 19th century. He prepared a questionnaire and inquired among his colleagues at the United States Geological Survey what it is that they exactly meant when saying bowlder, cobble, pebble, sand grain or clay particle. Perhaps most importantly, he asked them to provide the limiting dimensions that defined each of these words. He then shared his results with geologists specialised in in sediments and sedimentary rocks – in England and the US – and, based on the information compiled and the criticisms received, he proposed a new classification in a research article published in 1922, following that made by Johan August Udden a few years earlier.
Known as Udden-Wentworth scale, or simply as Wentworth scale, this classification of grain sizes remains widely in use today. The practical advantages that a unified vocabulary and scale had for the international community of geologists since 1922 come without saying. For historians searching for sediments in the massive flows of digitised words from the past, deposited in online repositories, the Udden-Wentworth scale is a signpost – but also a warning. On the one hand, the Wentworth scale and its translations to other languages provide us with a valuable set of keywords to search for sediments in the past. On the other, it reminds us that the meanings and sizes associated to these very keywords, before 1922, were not set in stone. Perhaps more importantly, the exercise of establishing a uniform, international scale with standardised scientific vocabulary necessarily involved pushing aside a wider, diverse vocabulary. These terms, however, may have remained in use in non-scientific circles, even if their usage is not common nowadays.
What may be useful for a historian willing to learn the past names of sediment is perhaps to reproduce the dull, systematic work that Wentworth did. To start compiling all words referring to limes, sands, pebbles and cobbles. To collect their definitions, paying attention to close languages, to dialects and etymologies. By repeating the work required to uniformize vocabulary and reduce its diversity, one may precisely gain access to this rich, older collection of terms. Take, for instance, the Spanish term tarquín, which pops up often when 19th century authors refer to the rich, fertilizing virtues of the matters floating in waters and flooded fields after a river surge or a flood. Still accepted in the current dictionary of Spanish but rarely used, it comes from the Arabic tarkīm, which referred to heaping, piling up. Beyond being an alternative way to refer to lime and clay and thus a valuable keyword for studying sediment in the past, tarquín exemplifies how the exercise of reconstructing old vocabulary may come with unexpected rewards for those interested in studying the past practices related to sediment. For the noun tarquín was also the root of a verb, entarquinar, which referred to the practice of fertilizing the fields using tarquín, as well as to the action of reclaiming of marshlands by letting the sediments from a watercourse fill them up. Beyond providing more keywords for online searches, reconstructing the vocabulary about sediment may open the door to related social practices – an entry point to a past where they named and did things differently.
*Santiago Gorostiza is a postdoctoral researcher at the Center for History at Sciences Po and member of the Shifting Shores team.