PHILIPP VON JOLLY
“In this field, almost everything is already discovered, and all that remains is to fill a few unimportant holes”.
Why does the feather always fall down? There should be some force which is dragging it downwards towards the earth. This force is called acceleration due to gravity. How this can be measured? Jolly was the first person to measure this using an instrument named Jolly Balance.
Johann Philipp Gustav Von Jolly was a German physicist and mathematician. He was born on 26th September 1809 in Mannheim. His Parents were Louis Jolly and Marie Eleonore Jolly. His father was an army captain and later became a merchant and also the Mayor of Mannheim. He studied Science in the Universities of Heidelberg and Vienna where he studied mechanics and technology. Later he went to the University of Berlin to pursue mathematics and physics. He received his Doctorate in the year 1834 from the University of Heidelberg. Later he was appointed as professor of Mathematics in Heidelberg in 1839 and in physics in 1846.
Jolly was regularly consulted by J.R. von Mayer who discovered the law of conservation of energy at the University of Heidelberg. During that time Jolly was concerned with questions of osmosis. Though his idea that equal amount by weight of salt and water are exchanged through a membrane were not proved to be correct, he however contributed to the clarification of this process. He started working as a teacher in the University of Munich since 1854 till his retirement shortly before his death. He was a very popular teacher. Jolly was also an exert consultant for the reorganization of Bavaria’s technical schools and German representative at the international conference on the meter held at Paris in 1872. He was also a member of the Bavarian Academy of Sciences and chairman for long duration of the Munich Geographical Society.
Jolly constructed various measuring devices like spring balance, the air thermometer used for determining the coefficients of expansion of gases in 1874, the eudiometer and the mercury pump. Also he greatly increased the accuracy of balances. He found in 1879 that the oxygen content of the “North Wind” masses of polar air is greater than that of the “South Wind” masses of tropical air. Jolly died on 24thDecember 1884 in Munich.