Publication Date:
2023-09-12
Description:
Pierre Perrault is often seen as the first modern hydrologist. In his famous work “De l'origine des fontaines”, he reviews the many theories concerning the hydrological cycle that classical philosophers had put forward. It had especially bothered most classical philosophers that the little bit of intermittent rain could not really give rise to the continuous flow as seen in rivers. Therefore, so it was reasoned, sources had to be fed differently, for example through water from the sea being pushed up and filtered through the mountains. Perrault, however, went on to show that for the Seine there was about six times more rainfall than runoff, thereby producing the first quantitative hydrological study. To the defense of the classics it should be mentioned that they tended to live in Karstic areas. Sadly, also in modern times, many “philosophers” still prefer to make up hydrological models instead of going out to actually measure stocks and fluxes. “De l'origine des fontaines” was dedicated to Christian Huygens, a Dutch scholar and diplomat, who used to make regular visits to the Perrault household in Paris, which also included Charles Perrault. Charles was not only collector and publisher of folk tales such as Cinderella, but also an important voice in overturning the blind faith in the classics. Pierre’s work also includes a long letter to Huygens in which he posed several questions. In the Huygens archive, the reply also exists but this reply is, as far as can be seen, not really known in the literature on the history of hydrology. In this presentation, the reply will be presented and analyzed. It is never made explicit what the discussions were that Pierre and Christian undoubtedly had but much can be inferred. It seems that the main contribution of Christian was to convince Pierre that it was not possible that the sources worked like a syphon. This was just the period in which it was shown that the “horror vacui” was not a real thing. The discussion focused especially on the generalizability of theories and observations. This led Christian to write, somewhat famously: “I believe that we do not know anything for certain, but everything probably”. He then goes on to present a well formulated Bayesian world view avant la lettre. Undoubtedly, Christian also encouraged Pierre to go out and measure the water balance of the Seine, leading to what can be seen as the first modern hydrological study.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
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