Monday, January 28, 2013

Isaac Roberts

Isaac Roberts was born January 27, 1829 in Groesback, near Denbigh, in northeastern Wales. His father, William Roberts, was a farmer. Even though his family moved to Liverpool, England when he was still young, it was not before he learned to speak Welsh. In 1844 he was apprenticed to a builder, working for John Johnson and Sons. As an apprentice he spent his evenings at the school in the Mechanic's Institute in Liverpool. After finishing his apprenticeship he remained with the same firm which he eventually became a partner and then owner. He retired from building in 1888 to devote his time to science. Initially he studied geology but he later switched his attention to astronomy for which he is mostly remembered.

Roberts was a pioneering astrophotographer of nebulae. His picture of what at the time was called the Andromeda nebula (now known as the galaxy Andromeda) was the first to show its spiral nature. At the time it was not known that there were other galaxies besides our own. It was not till 1924 that Edmund Hubble determined that the universe went beyond the Milky Way galaxy. In addition to his photography Roberts developed an instrument that engraved stellar images onto copper plates called a stellar pantograver. For his pioneering work in astrophotography he was awarded a gold medal by the Royal Astronomical Society. In 1890 he became a fellow of the Royal Society. In 1892 he received an honorary doctorate from Trinity College, Dublin.

Roberts died on July 17, 1904.


Jones, Bryn; "Isaac Roberts (1829-1904)"; Retrieved from:

R.S.B; "Isaac Roberts. 1829-1904"; Proceedings of the Royal Society of London (1904-1905)75:356-362

Isaac Roberts Wikiepedia Entry

Sunday, January 20, 2013

Alexandre-Emile Beguyer de Chancourtois

Alexandre-Emile Beguyer de Chancourtois was born on January 20, 1820 in Paris, France. At eighteen he began attending the school of mines at the Ecole Polytechnique. After completing his studies he joined a geological expedition to Turkey, Hungary, and Armenia. When he returned to Paris in 1848 he took a teaching position at the Ecole Nationale Superieure des Mines de Paris. He became a professor of geology in 1876. In 1875 he became the inspector of mines for France, a position he maintained until his death. As inspector of mines he introduced many safety measures including those to prevent a methane explosion.

He is best remembered for being the first to organize chemical elements into a system based on chemical similarities. Using the atomic masses obtained by Stanislao Cannizzaro, he developed a table of sixteen units, the atomic mass of oxygen, that wrapped around a cylinder, like the thread of a screw. This system was not widely accepted  by chemists because when it was originally published the printer did not understand the cylindrical system so there was no diagram printed and when it was later published in a geological journal it was ignored by chemists. The idea that chemical elements have periodic properties or chemical similarities as atomic mass increases eventually was developed by Dimitri Mendeleev into the first periodic table which was able to predict properties of yet undiscovered elements. The periodic table used today is based on that of Mendeleev.

He died on November 14, 1886 in Paris.


Fuchs, Edmond; "Obituary Notice on MA-E Beguyer de Chancourtois, Inspector General of Mines"; Retrieved from:

Strathern, Paul; Mendeleev's Dream: the Quest for the Elements; Macmillan; 2001

Alexandre-Emile Beguyer de Chancourtois Wikipedia Entry

Sunday, January 13, 2013

John Pringle Nichol

John Pringle Nichol was born on January 13, 1804 in Hunly Hill, in Forfarshire, Scotland. He was the eldest son of John Nichol a gentleman farmer and his wife Jane. He attended grammar school in Hunly Hill and went to Kings College in Aberdeen, winning highest honors in mathematics and physics. After graduation he served as headmaster in the grammar school at Dun. He held a number of headmaster positions until in 1836 he was appointed as the regius professor of astronomy at the University of Glasgow, a position he beat out Thomas Carlyle for. The duties of this position took little of his time, the rest of which he devoted to astronomical observation and  public lectures. Nichol's lectures were noted not only for their rhetorical power, but also scientific accuracy. His lectures were an inspiration to the young William Thompson.

Nichol's used his public lectures to popularize the nebular hypothesis, the theory that the solar system originated from a nebula. This is the current theory of how the solar system formed. Nebulae are large clouds of hydrogen gas. Gravity among the hydrogen molecules causes them to clump together. Stars form from the clumps of hydrogen when the gravitational pressure causes the hydrogen to begin nuclear fusion creating helium. This process takes over a hundred million years in the case of a sun sized star.

Nichol was responsible for the erection of new observatory on Horselethill in the west end of Glasgow and his family lived in a attached house. In addition to his public lectures Nichol was a prolific writer, publishing many popular books of science. His most famous book Views of the Architecture of the Heavens went through seven editions in seven years and won praise from popular writer George Eliot.

He died on September 19, 1858.


Clerke, Mary Agnes; "Nichol, John Pringle"; Dictionary of National Biography, 1885-1900; Vol. 40.

Anon.; "John Pringle Nichol"; Biography from the University of Glasgow.

John Pringle Nichol Wikipedia Entry

Sunday, January 6, 2013

Joseph Erlanger

Joseph Erlanger was born on January 5, 1875 in San Francisco, California. His parents, Herman and Sarah Erlanger, were Jewish immigrants to America and he was the sixth of seven children. After only two years of high school he enrolled in the University of California, Berkeley. He was the only one of his siblings to get a college education. He earned his bachelors degree in chemistry from UCB. He then went to the newly organized John Hopkins University medical school, where he received his medical degree in 1899. He remained at Johns Hopkins Hospital until 1906 when he went to the University of Wisconsin. After serving as a professor of physiology at the University of Wisconsin, he took a position as professor of physiology at Washington University in St. Louis, Missouri. He remained there until his retirement in 1946.

Erlanger's field was physiology. His studies included the physiology of the circulatory and nervous systems. His early research was on the human circulatory system. In 1904 he designed a sphygmomanometer, a device for measuring blood pressure. With it he studied relation between blood pressure and orthostatic albuminuria, a condition where protein appears in the urine of standing patients. During the First World War he studied wound shock and he helped develop therapies for it that were used on United States troops in Europe.

Working with his former student Herbert Gasser, Erlanger developed oscilloscope that could record nerve impulses. Up to that point it had been impossible to study nerve impulses directly, as they were too weak to be detected with the available technology. In 1920 H. Sydney Newcomer invented an amplifier that allowed nerve impulses to be detected. Using this amplifier, Erlanger and Gasser developed their oscilloscope. Nerve impulses are electrical currents generated by the movement of sodium ions into the nerve cell. When a nerve cell is stimulated protein channels in the nerve cell's cellular membrane open and sodium ions flood in. The movement of sodium ions into the cell causes a change in the membrane potential and the flood of sodium ions crossing the membrane into the cell moves down the length of the cell, conducted like an electrical current. Using the oscilloscope they developed Erlanger and Gasser found that larger nerve cells conduct impulses faster than smaller nerve cells and that different nerve fibers have different functions. For their pioneering work studying nerve fibers Erlanger and Gasser were awarded the 1944 Nobel Prize in Medicine and Physiology.

Erlanger died of heart failure on December 5, 1955.


Davis, Hallowell; "Joseph Earlanger: 1875-1955"; National Academy Press; 1970

Joseph Erlanger Nobel Biography

Joseph Erlanger Wikipedia Entry