a German Jewish and Russian engineer and physicist born in Potsdam. Jacobi worked mainly in Russia. He furthered progress in galvanoplastics, electric motors, and wire telegraphy. While studying the transfer of power from a battery to an electric motor, he deduced the maximum power theorem. Jacobi tested motors output by determining the amount of zinc consum...

a German Jewish and Russian engineer and physicist born in Potsdam. Jacobi worked mainly in Russia. He furthered progress in galvanoplastics, electric motors, and wire telegraphy. While studying the transfer of power from a battery to an electric motor, he deduced the maximum power theorem. Jacobi tested motors output by determining the amount of zinc consumed by the battery. With financial assistance of Czar Nicholas, Jacobi constructed in 1839 a 28-foot electric motor boat powered by battery cells. The boat carried 14 passengers on Neva river against the current. The boat fared at the speed of three miles for hour.

a Hungarian inventor, engineer, physicist, and Benedictine priest. He was also a member of the Hungarian Academy of Sciences, and author of several books. He is considered by Hungarians and Slovaks to be the unsung father of the dynamo and electric motor. Jedlik's best known invention is the principle of dynamo self-excitation. In 1827, Jedlik started experi...

a Hungarian inventor, engineer, physicist, and Benedictine priest. He was also a member of the Hungarian Academy of Sciences, and author of several books. He is considered by Hungarians and Slovaks to be the unsung father of the dynamo and electric motor. Jedlik's best known invention is the principle of dynamo self-excitation. In 1827, Jedlik started experimenting with electromagnetic rotating devices which he called electromagnetic self-rotors. In the prototype of the single-pole electric starter, both the stationary and the revolving parts were electromagnetic. In essence, the concept is that instead of permanent magnets, two opposed electromagnets induce the magnetic field around the rotor.

a Boston physician, scientist, and a military surgeon with the British Army in Nova Scotia and New York during the American Revolution. Born in Boston, Jeffries graduated from Harvard College and obtained his medical degree at the University of Aberdeen. He is best known for accompanying Jean-Pierre Blanchard on his 1785 balloon flight across the English Cha...

a Boston physician, scientist, and a military surgeon with the British Army in Nova Scotia and New York during the American Revolution. Born in Boston, Jeffries graduated from Harvard College and obtained his medical degree at the University of Aberdeen. He is best known for accompanying Jean-Pierre Blanchard on his 1785 balloon flight across the English Channel. Dr. Jeffries also played a large role in the trial for the Boston Massacre as a witness for the defense.

an English physician and scientist who was the pioneer of smallpox vaccine, the world's first vaccine. The terms "vaccine" and "vaccination" are derived from Variolae vaccinae (smallpox of the cow), the term devised by Jenner to denote cowpox. He used it in 1798 in the long title of his Inquiry into the...Variolae vaccinae...known...[as]...the Cow Pox...

an English physician and scientist who was the pioneer of smallpox vaccine, the world's first vaccine. The terms "vaccine" and "vaccination" are derived from Variolae vaccinae (smallpox of the cow), the term devised by Jenner to denote cowpox. He used it in 1798 in the long title of his Inquiry into the...Variolae vaccinae...known...[as]...the Cow Pox, in which he described the protective effect of cowpox against smallpox.

a German physicist and mathematician. e studied science in Heidelberg, Vienna and Berlin. After his studies, he was appointed professor of mathematics in Heidelberg in 1839 and in physics in 1846. He moved to Munich in 1854 where he took the position once held by Georg Simon Ohm. In 1854 he was knighted (and henceforth referred to as von Jolly). Jolly was fi...

a German physicist and mathematician. e studied science in Heidelberg, Vienna and Berlin. After his studies, he was appointed professor of mathematics in Heidelberg in 1839 and in physics in 1846. He moved to Munich in 1854 where he took the position once held by Georg Simon Ohm. In 1854 he was knighted (and henceforth referred to as von Jolly). Jolly was first and foremost an experimental physicist. He measured the acceleration due to gravity with precision weights and also worked on osmosis. He invented the Jolly balance, an instrument used for determining specific gravities.