Background
Du Crest was born into the aristocracy, and during a period in the military he became a Captain and military engineer by the age of 23.
cartographer engineer physicist
Du Crest was born into the aristocracy, and during a period in the military he became a Captain and military engineer by the age of 23.
During his time there, he mapped the Alps accurately using rudimentary tools. During his time in the parliament, Du Crest argued against the Genevan oligarchy and was an outspoken critic of the planned wall around Geneva. Du Crest fled to France in 1730, and an effigy was symbolically beheaded in 1735.
Whilst in France, Du Crest spent much of his time dedicated to scientific study.
He made advances in the study of temperature and came up with a recognised temperature scale which was used in Switzerland for many years. Du Crest was still outspoken regarding political issues, and lost the support of the people protecting him in France.
He was forced to flee again across Europe in 1744, stopping in major cities such as Zurich and Bern, until he became ill and was hospitalised in Bern"s Inselspital, where he was arrested in 1746. He was moved to Aarburg Castle, after getting involved with Samuel Henzi"s conspiracy, where he was held as a political prisoner for the remainder of his life.
Temperature scale Thermometer Mapping the Alps.
Du Crest devoted a significant portion of his life in exile to scientific study, making pioneering developments in cartography and the measurement of temperature. Du Crest believed that the temperature of the Earth was fundamentally fixed, based on the supposition that cellars and mines maintained an equal temperature. He used this "temperature of the terrestrial globe" as one fixed point, measured in a cellar 84 feet (26 m) below Paris Observatory, and the temperature of boiling water as a second fixed point. His scale between these points was then divided into one hundred equal degrees. Du Crest rejected mercury thermometers, stating that the substance was too difficult to purify, preferring instead alcohol which had passed the gunpowder test. He created a thermometer based the expansion of alcohol, calibrated using mercury. He further published works that explained his belief that alcohol expanded more regularly than mercury, and his experiments matched his scale more accurately than mercury did. During his time at Aarburg Castle he published many meteorological papers and created a cartographical drawing of the Alps as viewed from the castle. Without any modern equipment, such as a theodolite or telescope he instead used an eight-meter long gutter pipe, filled with water to measure levels and a small rod held in front of it, he could measure the heights of the peaks. He then used the Scheuchzer map of 1712 to calculate the distances away, and drew the first scientific panorama of the Alps.
In 1721, after leaving the army, he took up his place as a member of the Genevan parliament, as was his family"s right, specialising in security.
