Evangelista Torricelli – inventor of the barometer

Physicist's name lives on in scientific terminology

Evangelista Torricelli: a portrait by
Lorenzo Lippi, shortly before he died

The inventor of the barometer, Evangelista Torricelli, died on this day in 1647 in Florence at the age of just 39.

A disciple of Galileo, Torricelli made many mathematical and scientific advances during his short life and had an asteroid and a crater on the moon named after him.

Torricelli was born into a poor family from Faenza in the province of Ravenna.

He was given a basic education in Faenza and then sent to a Jesuit college to study Mathematics and Philosophy.

He studied science under the Benedictine monk, Benedetto Castelli, a professor of Mathematics at the Collegio della Sapienza, now known as the Sapienza University of Rome, who had been a student of Galileo Galilei.

Torricelli also became an admirer of Galileo and, after the great scientist’s Dialogues of the New Science were published, Torricelli wrote to him telling him he had read it with ‘delight’.

Galileo was condemned by the Vatican in 1633 for his beliefs and held prisoner at his villa in Arcetri. For the last three months of Galileo’s life, Torricelli worked for him there as his secretary and assistant.

Early barometers based on
Torricelli's findings

After Galileo’s death the Grand Duke Ferdinand II de Medici asked Torricelli to succeed Galileo as Chair of Mathematics at the University of Pisa.

In this role Torricelli solved some of the great mathematical problems of the day and described his observations in his book, Opera Geometrica. His work contributed to the eventual development of integral calculus.

Torricelli was also interested in optics and designed and built telescopes and microscopes.

But his most important invention was the mercury barometer, which he produced after he had discovered the principle of the barometer while trying to find a solution to the limitations of the suction pump in forcing water upwards.

He designed a kind of vacuum pump using mercury. He filled a metre-long glass tube, closed at one end, with mercury and inverted the tube so that the open end rested on the bottom of a vessel containing more mercury.  The mercury in the tube fell until it reached the point at which the weight of the mercury in the tube was balanced against the pressure exerted by air on the mercury in the vessel, leaving a vacuum at the top of the tube.

The statue of Torricelli in Faenza

Torricelli noted that the height of the mercury in the column varied from day to day, which he concluded was due to changes in atmospheric pressure. In 1644, he turned these discoveries into the first instrument to measure atmospheric pressure.

Scientific terms such as the Torricellian tube and Torricellian vacuum are named after the scientist, as is the torr, a unit of pressure in vacuum measurements. Torricelli’s Law refers to the speed of a fluid flowing out of an opening and Torricelli’s Trumpet relates to mathematical discoveries he made about infinity.

Torricelli died in Florence ten days after his 39th birthday and was buried at the Basilica of San Lorenzo.

Several Italian submarines have been named after Torricelli in honour of his work.

Travel tip:

A statue of Torricelli was erected in 1868 in Faenza, the city where he was born and educated, in recognition of all he had done to advance science during his short lifetime. The white marble statue can be found in the park of San Francesco in Corso Giuseppe Garibaldi.

An example of faience majolica-ware

Travel tip:

Faenza is in the Emilia-Romagna region, about 50 kilometres south east of Bologna. The city is famous for the manufacture of a type of decorative majolica-ware known as faience. It is also home to the International Museum of Ceramics, which has examples of ceramics from ancient times, the Middle Ages and the 18th and 19th centuries as well as displaying work by important contemporary artists. The museum is in Viale Baccarini in Faenza. For more information visit www.micfaenza.org.

More reading:

Galileo Galilei - brilliant physicist known as the 'father of modern science'

How Cosimo II de Medici maintained family tradition by supporting Galileo

Vincenzo Viviani - brilliant mathematician who worked with Galileo and Torricelli

(Picture of faience plate by Rosco CC BY-SA 2.5)


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Cesare Borgia – condottiero

Renaissance prince turned his back on the Church

Altobello Melone's portrait of Cesare Borgia

Cesare Borgia, the son of Pope Alexander VI, became the first person in history to resign as a Cardinal on this day in 1498 in Rome.

Cesare was originally intended for the Church and had been made a Cardinal at the age of 18 after his father’s election to the Papacy. After the assassination of his brother, Giovanni, who was captain general of the Pope’s military forces, Cesare made an abrupt career change and was put in charge of the Papal States.

His fight to gain power was later the inspiration for Machiavelli’s book The Prince.

Cesare was made Duke of Valentinois by King Louis XII of France and after Louis invaded Italy in 1499, Cesare accompanied him when he entered Milan.

He reinforced his alliance with France by marrying Charlotte d’Albret, the sister of John III of Navarre.

Pope Alexander encouraged Cesare to carve out a state of his own in northern Italy and deposed all his vicars in the Romagna and Marche regions.

Cesare was made condottiero - military leader - in command of the papal army and sent to capture Imola and Forli.

He returned to Rome in triumph and received the title Papal Gonfalonier from his father.

Niccolò Machiavelli

He subsequently took over Pesaro, Faenza and Rimini and laid siege to Piombino, later commanding French troops in the sieges of Naples and Capua, causing the collapse of Aragonese power in southern Italy.

Cesare was planning the conquest of Tuscany when he received news of his father’s death in 1503.

Machiavelli later wrote that had Cesare been able to win the support of Pope Julius II his success would have continued, but the new Pope went back on his promises.

Cesare was betrayed in Naples and imprisoned and his land was retaken by the Papacy.

He was transferred to Spain where his imprisonment continued in various castles. Eventually he escaped and tried to recapture his lands but he was ambushed by his enemies and received a fatal wound from a spear.

Cesare was originally buried inside the Church of Santa Maria in Viana in northern Spain but his bones were later expelled and buried under the street outside. He was dug up twice by historians and then reburied. After years of petitions being turned down because he had resigned as a Cardinal, he was finally moved back inside the church in 2007,  some 500 years after his death.

Travel tip:

Cesare Borgia was born in Rome and studied law at an educational institution, the Studium Urbis, which has now become the Sapienza University of Rome. It was founded in 1303 by Pope Boniface VIII as a centre for ecclesiastical studies and expanded in the 15th century to include schools of Law, Medicine, Philosophy and Theology.  It moved from being the papal university to the university of the city of Rome in 1870.  The main campus is situated just north of Termini Station.

Piazza Aurelio Saffi in Forlì.

Travel tip:

At the height of his power, Cesare Borgia controlled the Papal States, now part of the region of Emilia-Romagna in Italy. Faenza, Forlì and Rimini are among the historic cities he conquered. The area is one of the wealthiest in Italy, containing Romanesque and Renaissance cities.  It is a centre of production in the food and automobile industries, home to top-end car manufacturers such as Ferrari, Lamborghini and Maserati.

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Salvador Luria – microbiologist

Award winning scientist who advanced medical research

Salvador Luria, pictured at his desk at the Massachusetts
Institute of Technology at around the time of his Nobel Prize

Nobel prize winner Salvador Luria was born on this day as Salvatore Edoardo Luria in 1912 in Turin.

The microbiologist became famous for showing that bacterial resistance to viruses is genetically inherited and he was awarded a Nobel prize in 1969.

He studied in the medical school of the University of Turin and from 1936 to 1937 Luria served in the Italian army as a medical officer. He took classes in radiology at the University of Rome and began to formulate methods of testing genetic theory.

When Mussolini’s regime banned Jews from academic research fellowships, Luria moved to Paris but was forced to move again when the Nazis invaded France in 1940. Fearing for his life, he fled the capital on a bicycle, eventually reaching Marseille, where he received an immigration visa to the United States.

In America he met other scientists with whom he collaborated on experiments.  In 1943 Luria carried out an experiment with the scientist Max Delbruck that demonstrated that mutant bacteria can still bestow viral resistance without the virus being present.

Luria pictured with his American wife, Zella, at Cold
Spring Harbour, on the north shore of Long Island

He became chair of Microbiology at the Massachusetts Institute of Technology and received a number of awards and recognitions in addition to the Nobel prize.

Throughout his career, Luria was an outspoken political advocate. He protested against nuclear weapon testing, was an opponent of the Vietnam War and a supporter of organized labour.

Luria, an American citizen since 1947, died in Lexington, Massachusetts after a heart attack in 1991.

Travel tip:

Turin, the birth place of Luria, is the capital city of the region of Piedmont in the north of Italy. It is an important business centre, particularly for the car industry, and has a rich history linked with the Savoy Kings of Italy. Piazza Castello, with the royal palace, royal library and Palazzo Madama, which used to house the Italian senate, is at the heart of royal Turin.

The imposing main entrance to the Sapienza University
of Rome, built in the neoclassical style popular in the 1930s

Travel tip:

The University of Rome, where Luria studied, was founded in 1303 by Pope Boniface VIII.  Now known as the Sapienza University of Rome, it is one of the largest in Europe. The main campus, which was designed by Marcello Piacentini, is near Rome’s Termini railway station.

More reading:

Ernesto Teodoro Moneta - soldier who became a Nobel Peace Prize winner 

Dario Fo - critic of corruption who won Nobel Prize for Literature



(Photo of Rome University by Gongora CC BY-SA 4.0)

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