Jacques Triger (10 March 1801 – 16 December 1867) was a French geologist who invented the "Triger process" for digging through waterlogged ground using a pressurised caisson.
Triger was also deputy director of coal mining operations in
Chalonnes-sur-Loire
Chalonnes-sur-Loire is a commune in the Maine-et-Loire department in western France. It is located on the left bank of the river Loire in the Loire Valley UNESCO World Heritage Site area.
Geography
The town is in the heart of the Anjou, a hist ...
Mamers
Mamers () is a commune in the Sarthe department in the region of Pays de la Loire in north-western France. The neighboring communes are: Commerveil, Saint-Longis, Saint-Rémy-des-Monts, Origny-le-Roux, Suré. Mamers is twinned with the town Ma ...
,
Sarthe
Sarthe () is a department of the French region of Pays de la Loire, and the province of Maine, situated in the '' Grand-Ouest'' of the country. It is named after the river Sarthe, which flows from east of Le Mans to just north of Angers. It ha ...
, France, on 10 March 1801. He studied at La Flèche and then in Paris, where he met
Louis Cordier Pierre Louis Antoine Cordier (31 March 1777 – 30 March 1861) Annales.org, accessed 20 September 2009 was a French in 1825. Cordier was an eminent French geologist, who taught Triger his first lessons in geology, where he quickly took interest in the technical challenges of this industrial sector. At 32 years old, together with skilled managers, Triger developed new industries in Sarthe and
Mayenne
Mayenne () is a landlocked department in northwest France named after the river Mayenne. Mayenne is part of the administrative region of Pays de la Loire and is surrounded by the departments of Manche, Orne, Sarthe, Maine-et-Loire, and Ill ...
. In this period, he developed and launched three coal mines, a paper mill and a sawmill.''Notice sur la vie et les travaux de M. Triger'', Société Géologique de France, Tome 25 des bulletins, 1868
In 1833, Triger was left by the woman he intended to marry. This plunged him deeply into his work: the production of gravel from dolomite rock, the construction of public fountains in Mamers and the detailed study of phreatic groundwater tables near Le Mans.
In 1834, Triger started the study and geological investigation of his region – Sarthe and Mayenne. These investigations and discussions with Louis Cordier drove him to
Anjou Anjou may refer to:
Geography and titles France
* County of Anjou, a historical county in France and predecessor of the Duchy of Anjou
**Count of Anjou, title of nobility
*Duchy of Anjou, a historical duchy and later a province of France
**Duk ...
( Maine-et-Loire), where coal was craft-mined. Thus, in 1839, Triger began to look at the
Loire
The Loire (, also ; ; oc, Léger, ; la, Liger) is the longest river in France and the 171st longest in the world. With a length of , it drains , more than a fifth of France's land, while its average discharge is only half that of the Rhône ...
river and the way to reach solid rock underneath about 20 meters of waterlogged soil. After reading many articles on compressed air, he was convinced that he could use it to help dig through this layer of soil. He does not lie on the idea of using compressed air, but on the invention of the airlock – to pass from the pressurized zone of the caisson to the zone of atmospheric air pressure, and especially in finding a practical way to utilize the technique on an industrial scale. With the financial and administrative support of Emmanuel de Las Cases, five steel shaft linings were drilled by this invention, which was subsequently adapted and applied to dig foundations, bridges and many tunnels.
Helped by a liking for travel, Triger gradually established the first geological map of Sarthe County. After more than 20 years of research, the document was presented in 1853 at the Geological Society of France. The topographic background, support of the geological layers were designed by Triger himself. To design this document, he had to study all the fossils in his county and deal with some of the mysteries at that time, such as the structure of the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...
terrain of Maine or the study of the Silurian- Devonian- Carboniferous lands in the west part of France.
Triger wanted the designation of the geological strata to be borrowed from paleontology (fossil names). He saw in this new system "the precious advantage of a universal language that one would understand everywhere, without comments and which would easily help the geologists from all regions of the globe to communicate". Triger would come to constitute regular geological cross-sections of the eastern France. This work was carried out by a team of geologists directed by Triger: geological sections from Paris to Brest, from Le Mans to Angers, from Paris to Rennes, and from Vendôme to Brest.
Triger was also a
paleontologist
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...
, part of the first team to excavate the archaeological site of Roc-en-Paille (
Chalonnes-sur-Loire
Chalonnes-sur-Loire is a commune in the Maine-et-Loire department in western France. It is located on the left bank of the river Loire in the Loire Valley UNESCO World Heritage Site area.
Geography
The town is in the heart of the Anjou, a hist ...
, Maine-et-Loire). His very large collection of rocks, fossils and minerals is now displayed at the Museum of Natural History in
Angers
Angers (, , ) is a city in western France, about southwest of Paris. It is the prefecture of the Maine-et-Loire department and was the capital of the province of Anjou until the French Revolution. The inhabitants of both the city and the pr ...