Jacques Alexandre César Charles was born in Beaugency, France on the 12th of November 1746 and he died April 7th, 1823 in Paris. He was a chemist, physicist, mathematician, inventor and aeronaut. He also was a clerk in the finance ministry who developed an interest in science, especially in the preparations of gases and also experimented with electricity. He produced several inventions including a hygrometer and reflecting goniometer and he improved the Gravesande’s heliostat and Fahrenheit’s aerometer. Although he produced the previously mention inventions his fame is mainly associated with the gas law named after him – “Charles Law”. In 1795 he was elected to the Academie des sciences in Paris and he became a professor of physics at the Conservatoire des Arts at Metiers in Paris. He published many papers but they are mainly concerned with mathematics.
This is a photograph of Jacques Alexandre Cesar Charles.
He knew that in 1766 the British scientist Henry Cavendish had isolated a gas that was 4 times lighter than air – hydrogen. So with this evidence on the 27th of August 1783 Charles’ first balloon was released. The balloon was made of silk with a cover of rubber solution varnish to keep the hydrogen inside. One of the spectators was the American Ambassador to France Benjamin Franklin who replied, when some one asked him of what possible use this new invention could have:
“And of what use is a new-born baby?”
He knew that in 1766 the British scientist Henry Cavendish had isolated a gas that was 4 times lighter than air – hydrogen. So with this evidence on the 27th of August 1783 Charles’ first balloon was released. The balloon was made of silk with a cover of rubber solution varnish to keep the hydrogen inside. One of the spectators was the American Ambassador to France Benjamin Franklin who replied, when some one asked him of what possible use this new invention could have:
“And of what use is a new-born baby?”
The balloon came down to earth about 45 minutes later in a field near to the little village of Gonesse. It was here that the local farmers gave their famous display of the eternal human fright of new technology and strange phenomena. With pick axes and spades they attacked the ‘monster’ that had tumbled down from the sky, inspired by the beast’s behaviour to sigh and groan and emit a horrible smell. The horsemen who had been following the balloon could only save some torn remains by the time they arrived. Charles’ first balloon had reached a height of approximately 2 miles and had covered 43km over land before it landed.
In 1787 Charles was working with oxygen, nitrogen, carbon dioxide and hydrogen and had deduced a law concerning gases but did not publish it, so it was not until 15 years later in 1802 another chemist called Joseph-Louis Gay-Lussac published his own experimental results and that is why the law is sometimes called the Gay-Lussac Law instead of Charles Law. The law is:
V1
= V2
T1
T2
This can be explain as follows:
“If a gas is held at a constant pressure, the volume is directly proportional to the absolute temperature (measured in degrees Kelvin)”
This means that if a gas is heated to double its original temperature then its volume will also double. This is shown by the following diagram which is a graphical representation of Charles’ Law.
Charles’ Law is a special case of the general gas law, which states that the product of the absolute temperature (t) and a constant equals the product of the pressure (p) and the volume (v) or pv=kt, and can be derived from the kinetic theory of gases under the assumption of a perfect/ ideal gas. Measurements show that, at constant pressure the thermal expansion of real gases is nearly the same at sufficiently low pressure and high temperature, showing that Charles’ law is approximately valid.