Isaac Mathieu Crommelin: His Books, His Legacy

- by Miff Crommelin

Isaac Mathieu Crommelin (1730-1815) was a man of many talents and interests who lived through a turbulent period in France's history. He was also a man who took the trouble to write down his thoughts, political views, and experiences for the sake of posterity. He was a man in love with history, art, archaeology, philosophy, music, mechanics, science, religion, medicine, writing, family history, business, as well as a man of practicality and common sense whom one could trust and turn to in times of extreme peril. Although we have no portrait of him, we are told in his Memoirs that Isaac bore an uncanny resemblance to Benjamin Franklin for whom he was occasionally mistaken.

The Teacher and Pupil

In 1775 he published a 3-Volume Encyclopedia on Basic Arts and Sciences intended to bring together facts about a multitude of disciplines for the edification of a young student. In Isaac's own drawing which appears next to the first page of his Encyclopedia we see a young man consulting a book of knowledge and its Author who is perhaps God or some wise spirit such as 'Mother Nature'. At their feet lies a couple of other books labelled 'Theology' and 'Buffon' which signify the equal importance of both the spiritual and physical worlds - the dual spheres in which the body and spirit of living human beings interact. Georges-Louis Leclerc, Comte de Buffon (1707-1788), a contemporary of Isaac and one of the world's greatest scientists, was a notable French authority who wrote a 44-volume encyclopedia called Historie Naturelle (Natural History) which described everything known about the natural world.

Surrounding the 'Teacher and Pupil' we see contrivances associated with man's quest for knowledge and advancement: a globe, a spinning wheel, books, bottles of medicines and chemicals, implements for drafting and measurement, a human skeleton, an artist's brushes and palette, sheets of music, the drum from some primitive Indian tribe, a glass retort for chemical experimentation, and a diagram showing planets revolving around the sun. On the lectern stands a copy of Newton's Principia, his concept of gravity that set the stage for modern physics and astronomy.

Isaac's Memoirs, written in 1807, relate how, while staying in London as a student to learn English and science under his teacher, Mr. Burgh, he had occasion to present an astronomy lesson to two young men at St. James palace. These men were the Duke of York and his brother, the Prince of Galles - the man who later became King George III, the king who George Washington fought against in the American Revolution! Equipped with a mechanical model devised by his teacher, Isaac demonstrated how the earth rotated on its axis and how the seasons were a result of planets revolving around the sun; how eclipses and the phases of the moon occurred; and how tides resulted from the moon's gravitational attraction on the Earth's oceans. Around this time Isaac was particularly intrigued with magnets and how magnetism could be induced into a flat piece of iron by simply stroking it outward from the centre in both directions while facing North.

First page of the Table of Contents to Vol. 1 of Isaac's 'Encyclopedia'

The Table of Contents of his Encyclopedia shows the wide diversity of topics that Isaac chose to address. In the first few pages alone subjects such as mountains, rivers, marine life, atoms, the origin of planets, and the diverse opinions of various early Greek philosophers are touched upon!

His Memoirs [which appear on the Crommelin Family website] also relate how he was asked to personally escort Monsieur Buffon's son from Châlons to the home of Voltaire in Ferney (close to the border with Switzerland). This 13-year-old boy had undoubted mathematical ability by showing Isaac how to calculate the volume of water in Lake Nantua which they came across on their journey. Having resided in the home of Voltaire for a short time, Isaac's impressions are most revealing and amusing.

Around the time that he wrote his Encyclopedia, Isaac was living in Autun, France, and a member of the Academy of Sciences, Arts and Literature of Dijon. As a member of this prestigious society he wrote a number of papers from 1771 to 1778 on such esoteric subjects as the antiquities found around Autun; comments on the effects of thunder; a paper on coal mining and the model of a machine to raise the broken coal to the surface; Oronoko, a Tragedy in verse and in five acts; and the model for a more efficient chimney. Isaac's Memoirs also recount how he built several moving tableaux - mechanical scenes where levers, springs, gears, and cams were used to animate miniature people and animals busily engaged in everyday domestic activities. He even ground the lenses for his own spectacles which he found preferable to any which were then commercially available. Isaac also mentions that he took music lessons from the brother of French composer, Jean-Philippe Rameau. And in one amusing anecdote he had access to an original portrait by the French master, Quentin de la Tour, which he managed to copy so faithfully that he fooled the 'art critics' of his day!

In recent years Govert Deketh and I have sought to acquire a collection of Isaac's publications. Happily, we have enjoyed some success in this endeavour. One notable acquisition was a 'scrapbook' in which Isaac jotted down various articles of interest which he came across while studying reference material in libraries and volumes by other authors. In his own neat handwriting he thus wrote his own 'Book of Knowledge' that was never published but which comes complete with an index. This rare hand-written manuscript is the only copy in existence. Isaac may have used this work as a reference before writing his 3-volume Encyclopedia and it may even have inspired him to do so. Thus we have assigned an arbitrary date of 1770 to this scrapbook.

Cover and index of 'Snippets of History and Literature'
- a handwritten scrapbook of information compiled by Isaac Mathieu Crommelin

Some of the subjects contained in this manuscript include the Dutch East India Company; the Death of William, the Prince of Orange; the Articles of the Union of Utrecht which formed the Netherlands; and the origin of the French emblem, the Fleur de Lis.

Another oddity that struck Isaac's fancy was a book in English about the Life and Adventures of Tsonnonthouan, king of an Indian nation called the Round Heads. He therefore set about to translate the whole book into French and have it published in 1787. The original book seems to have vanished from the world of literature but at least Isaac's French translation remains to keep Tsonnonthouan's memory alive for posterity! This isn't the only fanciful book that Isaac decided to publish. He wrote another one called Don Quichotte Femelle in 1773 which is a female version of Don Quixote; then in 1808 Mes Reveries, and in 1809 another 2-vol. book entitled Mes Radotages [My Random Musings] which includes essays on diverse topics such as Geography, Meteorology, Zoology and Philosophy. Indeed, Isaac had a fertile brain and was a man ahead of his time!

'Mes Radotages', a book in 2 volumes published in Paris, 1809

Beginning around 1789 France was gripped in a bloody revolution that eventually destroyed its monarchy and Ancien Regime - a system of feudalism built upon class distinction and privileges which favored the church and nobility at the expense of the common people. Isaac was an honest hardworking bureaucrat when the winds of change shook France but because of his refusal to help Robespierre in writing propaganda for the revolutionary cause he too was inevitably denounced, arrested and imprisoned in the Chateau of St. Germain-en-Laye on ludicrous charges. He spent a year confined in a room on the top floor of this prominent chateau in Paris. This is where he wrote the notes for his book Espion de la Revolution Francaise which he smuggled out when he was released, a few months after Robespierre was executed.

Chateau de St. Germain-en-Laye in Paris

His encounter with Robespierre and the account of his arrest during the French Revolution is given in his Memoirs. This ordeal is subtantiated by various official documents such as the record of his arrest and release which still exist in French archives.

Isaac's arrest in 1793 during the Reign of Terror

Isaac's arrest record reads in part, "Isaac Mathieu Crommelin, native of Saint Quentin in the District and Departement of Aisne, aged 63 years, presently confined at Montagne-bon air [the jail of St-Germain's revolutionary committee], married, his wife aged 56 living at Saint Quentin, they have no children. At the Montagne detention centre since 17 September, arrested by the Committee [of Revolutionary Surveillance] after being denounced for professing principles that were aristocratic and divisive..." On this day, September 17, 1793, the Law of Suspects was promulgated - a decree that called for a general roundup of all suspects of 'treason', for example: those who, by their conduct, associations, comments, or writings have shown themselves partisans of tyranny or federalism and enemies of liberty. Isaac was first imprisoned at the Convent des Récollets in Paris before being transferred to the Chateau of St. Germain.

A point of interest regarding his arrest record (above) is the use on two occasions of the words 'vieux stile' ('old style') with regard to dates, i.e., 'September, Old Style' and 'August, Old Style'. Around 1792 the revolution brought with it a completely new French Revolutionary Calendar which had 12 months of 30 days each, each month having 3 weeks of 10 days each, the 'week' now being called a 'decade'. The 'new year' began in Autumn with the months Vendémiaire (meaning "grape harvest"), Brumaire (meaning "fog"), Frimaire ("frost"), Winter: Nivôse ("snowy"), Pluviôse ("rainy"), Ventôse ("windy"), Spring: Germinal ("germination"), Floréal ("flower"), Prairial ("pasture"), Summer: Messidor ("harvest"), Thermidor ("summer heat"), Fructidor ("fruit").

The year "1" on the new French Revolutionary Calendar didn't begin with Christ's crucifixion, but on September 22, 1792, the day that the French First Republic was proclaimed - one day after the Convention abolished the monarchy. Time was 'decimalized' under the French Revolutionary (Republican) Calendar: a day was divided into ten hours, each hour having 100 decimal minutes, and each decimal minute into 100 decimal seconds. When the prison official penned Isaac's arrest record, the dating system was still in transition, therefore he simply wrote 'September' and 'August' and duly noted 'Old Style'!

Release record showing dates of Isaac's confinement
Arrested 17 September, 1793; Released 28 November, 1794

Following his release, Isaac returned to his former bureaucratic station greatly impoverished because of unscrupulous treatment by his government employer, a devastated economy, and currency that had become virtually worthless. Besides his Memoirs which records his experiences while in prison, Isaac wrote a two-volume book entitled Espion de la Revolution Francaise (Witness to the French Revolution) to document his understanding of why the revolution occurred and some of the dramatic events that transpired. Published in 1797, this book appears on the Crommelin Family website but the English translation is still incomplete.

Isaac's account of the French Revolution

We also have images of Isaac's birth registry (1730), Last Will and Testament (1809), and death registry (1815). After so many years it seems remarkable that we could have such a complete picture of the life and times of a unique individual who was interested in virtually every aspect of human activity and eager to pass his knowledge on to others. Amazingly, he had the opportunity to meet personally with notable historical figures such as King George III, Voltaire, Diderot, Necker, the son of Buffon, Robespierre, Rouget de l'Isle (composer of the French anthem, Marseillaise), Choiseul, Vergennes, the water diviner, Bléton, and the astonishing cameo-maker, Nini.

Isaac's L'Iliade Travestie

The book L'Iliade Travestie was a project that Isaac started. He had parodied several epic poems from Homer’s Iliad and a society of ‘scientists, officers, magistrates, writers, etc.’ decided to expand and finish his handwritten notes into a book that was published in Isaac’s honour in 1831. In all his writings Isaac refers back to antiquity for examples and precursors to contemporary events. This exhibits his knowledge of history, and the importance he placed on the past in order to comprehend the present.

It gave me much satisfaction to study Isaac Mathieu Crommelin; to research his exploits and to help save them for posterity. In this effort I am most grateful to Maryse Trannois for her ceaseless efforts to find documents pertaining to Isaac, and for taking the time to photograph and type the many pages of his books to aid me in translating them! I also wish to acknowledge Hannetje Crommelin's great contribution in typing Vol. 2 of Isaac's Espion book for translation purposes. Again I am indebted to Govert Deketh for his encouragement and financial assistance in helping to acquire a number of rare books. The 'Isaac Mathieu Crommelin Project' was certainly an international team effort involving people from France, Switzerland, Holland and Canada! Incidentally, in 1792, the year before Isaac was captured and imprisoned, Capt. George Vancouver was engaged in surveying land that later became the City of Vancouver, Canada.

Family members who wish to receive a CD containing an anthology of Isaac Mathieu Crommelin's writings for their family records should contact the author, Miff Crommelin, at