Perrault P
Full Name: Pierre Perrault
Achievements: Hydrology
Born: c. 1611; Paris, France
Died: 1680; Paris, France (Aged about 69)
Field & Discipline: Science; Hydrology
Language: French
Father: Unknown
Mother: Unknown
Siblings: Four, of whom: Claude (physician, scientist and architect of the Louvre); Nicolas (theologian); Charles (critic, author of the Mother Goose fairy tales)
Spouse: Unknown
Children: Unknown
Education: Unknown
Major Work:
"The Origin of Springs"
Life & Times:
Perrault, like his father, was a lawyer and joined the French government service as an administrator. In 1654, he bought himself the post of receiver-general of finances (tax collector) for Paris, employing his brother, writer [his brother was] Charles Perrault*, as tax officer.
In 1664, Perrault was caught borrowing on the current year's revenue and was dismissed by chief minister [fired by] Colbert*, a reformer cleaning up the tax department and tax system. He was, however, able to ensure the choice of another brother, Claude, to be architect of the Louvre colonnade, against the rival architect tendering for the job, [blocked work of] Bernini*
In 1674, Perrault anonymously published a work that would prove of great scientific significance, "On the Origin of Springs," dedicated to [dedicated work to] Christiaan Huyghens*. Summarizing earlier theories about the origin of springs, the work suggested that rainfall alone was enough to sustain the flow of springs and rivers.
To prove his theory, Perrault studied a substantial section of the Seine River, beginning at its source, northwest of the city of Dijon, to Aynay-le-Duc (now Aignay-le-Duc). He calculated the annual rainfall for that section of the river, then the total drainage (subtracting the losses due to "feeding the trees, herbs, vapors, [and] . . . swellings of the river when it rains"), coming up with a figure representing the sustained runoff.
He then estimated the annual flow of the Seine by comparing its flow with that of the Gobelins River near Versailles, which had been measured previously. He concluded that only one-sixth of the annual rainfall was needed to sustain the river flow, for the first time scientifically proving that rainfall is more than adequate to supply river flow.
After his death, Perrault's work was continued by [work continued by] Mariotte*, who, in 1678, began his hydrostatic investigations using more sophisticated measuring techniques than Perrault had at his disposal.
His findings led to the notable work: "The Motion of Water and other Fluids" (1686). The other half of Perrault’s concept of the hydrologic cycle, (that enough water evaporated from oceans and rivers to come down as rainfall) was experimentally proved by [theory supported by] Halley* during the 1690s.
Extra Connections: Influenced by [influenced by] Mersenne*
Assessment: Through his study of the Seine River in France, became the Father of Hydrology
Oneliner: Pierre Perrault, early hydrographer
Bibliography:
- Dictionary of Scientific Biography.
- Hallays, A., Les Perrault, Paris, 1926.