Baliani, GB

Full Name: Giovanni Battista Baliani

Achievements: The first to speculate on the existence of atmospheric pressure.

Born: 1582; Genoa, Italy

Died: 1666; Genoa, Italy (Aged 84)

Field & Discipline: Science; Physics

Language: Italian

Father: Unknown

Mother: Unknown

Siblings: Unknown

Spouse: Unknown

Children: Unknown

Education: Unknown

Major Work:

“De motu naturali gravium solidorum Ioannis Baptistae Baliani partritii genuensis”  (1638)

Life & Times:

Giovanni Battista Baliani studied law before entering the service of the Genovese Republic, for which he worked for most of his life. His scientific interests seem to have begun around 1611, when he was commander of the fortress of Savona, and noticed that cannon balls of very different weight fell at the same speed.   In 1613 Baliani met Filippo Salviati, who wrote about him to [worked with] Galileo*. Galileo and Baliani then began a long correspondence, which began on the subject of the experimental calculation of the weight of air.  In 1615 Baliani visited Galileo at Florence.

Baliani was as nominated Governor of Sarzana in 1623, and became a member of the Genovese Senate the following year.  During the 1620’s he became interested in engineering problems linked to pneumatics, and in 1630 wrote to Galileo asking for advice on the reasons for the failure of a siphon pump which was supposed to carry water over a hill about 60 feet high.

In his letter, Baliani correctly theorized that the action of a siphon was affected by atmospheric pressure (he was the first person to do so), but doubted that the total weight of a column of air many miles high could be less than that of a 30-foot column of air. 

In his reply, Galileo described the working limits of a suction pump, and rejected the idea of atmospheric pressure.   Galileo argued that the force of the vacuum was enough to lift a column of water with a pump up to a maximum height of around 30 feet but, he argued, beyond this limit the force of the vacuum was insufficient, and the column of water disintegrated. This, according to Galileo, was the reason for the failure of Baliani's siphon.

During the 1630s Baliani became intensely interested in developments surrounding problems of motion, and in 1638 he published a short treatise on the motion of heavy bodies, “De motu naturali gravium solidorum,” which he reprinted with many additions in 1646.  In the 1638 edition Baliani arrived independently at several of the conclusions arrived at by Galileo in his “Discourse on two New Sciences,” which appeared in the

same year.

In 1647, Baliani returned to Savona as governor of the fortress, and published a treatise in which he offered a chemical explanation for the plague and its contagious nature, and put forward a argument on the principle that, without wars and pestilence, the rate in growth of the human population as related to arable land and food production would necessarily result in famine.

For this achievement, Baliani can be regarded as a predecessor of the English economist [anticipated] Malthus*.

In 1649 he left Savona and returned to Genoa, where he was elected to the Genovese Government and remained until his death.

Extra Connections: His work related to that of [work related to] Torricelli*.

Assessment: A major figure in the work preceding the discovery of the vacuum

Oneliner:  GB Baliani,  seventeenth-century Italian physicist

Bibliography:

• Dictionary of Scientific Biography.