René Prudent Patrice Dagron (17 March 1819 – 13 June 1900) was a French

French people

The French are a nation that share a common French culture and speak the French language as a mother tongue. Historically, the French population are descended from peoples of Celtic, Latin and Germanic origin, and are today a mixture of several ethnic groups...

 photographer and inventor. He was born in Aillières-Beauvoir

Aillières-Beauvoir

Aillières-Beauvoir is a commune in the Sarthe department in the region of Pays-de-la-Loire in north-western France.-References:*...

, Sarthe

Sarthe

Sarthe is a French department, named after the Sarthe River.- History :The department was created during the French Revolution on March 4, 1790, pursuant to the law of December 22, 1789, starting from a part of the province of Maine which was divided into two departments, Sarthe to the east and...

, France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

.
On 21 June, 1859, Dagron was granted the first microfilm patent

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

 in history. He grew up in rural France but he left for Paris

Paris

Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 at an early age. In Paris he distinguished himself in the study of Physics

Physics

Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

 and Chemistry

Chemistry

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

. As a chemistry student Dagron became interested in Daguerrotypes when the process of producing them was announced on August 19, 1839. After graduation, Dagron established a photographic portrait studio in Paris. While in Paris Dagron became familiar with the collodion

Collodion

Collodion is a flammable, syrupy solution of pyroxylin in ether and alcohol. There are two basic types; flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible cellulose film...

 wet plate and collodio-albumen dry plate

Dry plate

Dry plate, also known as gelatin process, is an improved type of photographic plate. It was invented by Dr. Richard L. Maddox in 1871, and by 1879 it was so well introduced that the first dry plate factory had been established...

 processes which he would later adapt to his microfilm techniques. Dagron is also considered the inventor of the miniature photographic jewels known as Stanhopes

Stanhope (optical bijou)

Stanhopes or Stanho-scopes are optical devices that enable the viewing of microphotographs without using a microscope. They were invented by René Dagron in 1857. Dagron bypassed the need for an expensive microscope to view the microscopic photographs by attaching the microphotograph at the end of a...

 because a modified Stanhope lens

Stanhope lens

A Stanhope lens is a simple, one-piece microscope invented by Charles, the third Earl of Stanhope. It is a cylinder of glass with each end curved outwards, one being more convex than the other. The focal length of the apparatus is at or within the device so that objects to be studied are placed...

 is used to view the microscopic picture attached to the lens.

History

In 1857 John Benjamin Dancer

John Benjamin Dancer

John Benjamin Dancer was a scientific instrument maker and inventor of microphotography. He also pioneered stereography. By 1835, he controlled his father's instrument making business. He was responsible for various inventions, but did not patent many of his ideas. In 1852, he invented the...

's microfilms were exhibited in Paris for the first time and Dagron immediately saw their potential. He used the concept of microphotography to produce simple microfilm viewers which he would later manufacture and incorporate into novelties and souvenir products as well as other applications. Soon after that, Dagron encountered problems with imitators and people infringing on his patents. On 21 June 1859, Dagron was granted the first microfilm patent in history and in the same year he introduced his photographic miniature Stanhope toys and jewels during the International Exhibition in Paris.

In 1862, Dagron exhibited his miniature Stanhope viewers during London's International Fair. In the London Fair he received an honourable mention and presented a set of microfilms to Queen Victoria. The same year Dagron published his book: "Cylindres photo-microscopiques montes et non-montes sur bijoux, brevetes en France et a l'etranger". Translated as: "Photomicroscopic cylinders mounted and non-mounted on jewels: Patents in France and abroad". In 1864 Dagron published the 36 page booklet Traite de Photographie Microscopique in which he described in great detail the process he invented in producing microfilm positives from normal size negatives. The microfilm industry is considered to have been created by him, starting in 1859 when he obtained his patent.

During the 1870-71 siege of Paris

Siege of Paris

The Siege of Paris, lasting from September 19, 1870 – January 28, 1871, and the consequent capture of the city by Prussian forces led to French defeat in the Franco-Prussian War and the establishment of the German Empire as well as the Paris Commune....

 by the Prussia

Prussia

Prussia was a German kingdom and historic state originating out of the Duchy of Prussia and the Margraviate of Brandenburg. For centuries, the House of Hohenzollern ruled Prussia, successfully expanding its size by way of an unusually well-organized and effective army. Prussia shaped the history...

n armies Dagron assisted his country by providing a novel way of communication with the free areas outside of the capital. He sent carrier pigeons with messages in microfilms across German lines. This was the first important application of microfilm.

During the siege of Paris, Dagron proposed to the authorities to use his microfilming process to carry the messages by carrier pigeons. Rampont, the man in charge of the carrier pigeon program, agreed and a contract was signed on 11 November. According to the contract Dagron was to be paid 15 francs

French franc

The franc was a currency of France. Along with the Spanish peseta, it was also a de facto currency used in Andorra . Between 1360 and 1641, it was the name of coins worth 1 livre tournois and it remained in common parlance as a term for this amount of money...

 per 1000 characters photographed. A clause in the contract, signed by an official named Picard, gave Dagron the title of "chief of the photomicroscopic correspondence postal service" mentioning in French

French language

French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

: "M. Dagron a le titre de chef de service des correspondences postales photomicroscopiques. Il relève directement du Directeur Général des Postes," which translates as "Mr. Dagron has the title of the chief of the photomicroscopic correspondence postal service. He reports directly to the Director General of the Post Office."

After a period of difficulties and through hardships brought on by the war and the lack of equipment, Dagron finally achieved a photographic reduction of more than 40 diameters. The microfilms so produced weighed approximately 0.05 gram

Gram

The gram is a metric system unit of mass....

s each and a pigeon was able to carry up to 20 at a time. Up to that point a page of a message could be copied in a microfilm approximately measuring 37 mm by 23 mm but Dagron was able to reduce this to a size of approximately 11 mm by 6 mm which was a significant reduction in the area of the microphotograph.

Dagron photographed pages of newspapers in their entirety which he then converted into miniature photographs. He subsequently removed the collodion film from the glass base and rolled it tightly into a cylindrical shape which he then inserted into miniature tubes that were transported fastened on the wings of pigeons. Upon receipt the microphotograph was reattached to a glass frame and was then projected by magic lantern

Magic lantern

The magic lantern or Laterna Magica is an early type of image projector developed in the 17th century.-Operation:The magic lantern has a concave mirror in front of a light source that gathers light and projects it through a slide with an image scanned onto it. The light rays cross an aperture , and...

 on the wall. The message contained in the microfilm could then be transcribed or copied. By 28 January 1871, when Paris and the Government of National Defense

Government of National Defense

Le Gouvernement de la Défense Nationale, or The Government of National Defence, was the first Government of the Third Republic of France from September 4, 1870, to February 13, 1871, during the Franco-Prussian War, formed after the Emperor Louis Napoleon III was captured by the Prussian army. The...

surrendered, Dagron had delivered 115,000 messages to Paris by carrier pigeon.