
On 6 Sep 1811, James Melville Gilliss was born, the U.S. naval officer and astronomer who founded the Naval Observatory in Washington, D.C., the first U.S. observatory devoted entirely to research. When he started out, he taught himself astronomy, at a time when there was no fixed astronomical observatory in the U.S., and very little formal instruction. In 1838, he became officer-in-charge of the Depot of Charts and Instruments, forerunner of the U. S. Naval Observatory. Accurate star charts were essential for the navigation of ships, since they provided for the measurement of an observer's position. Upon his death, a Biographical Memoir of James Melville Gilliss was presented before the National Academy (1866). As you read it, you can reflect on the extensive, dedicated work required building up the body of knowledge for effective navigation at sea, long before GPS location finding was as available from the nearest cell phone. The name of Gilliss now goes mostly without recognition, but his work was of great significance in his era.

On 6 Sep 1908, Louis Essen was born, the English physicist who invented the first practical atomic clock, a device capable of measuring time more accurately than any previous clock. Now, precision time has become imbedded in modern activities. Today's book pick is: , by who picks up the history of time-keeping with astronomical methods, and ends with the GPS satellites which give nanosecond accuracy. With such a small time increment, compensation is required for the effects of special and general relativity. The largest part of the book deals with the development of time-keeping, and includes the story of the revolution brought about with atomic clocks, how they work, how more than 200 of them are used to form the world's time, and why we need leap seconds. No longer is time a function of the motion of the earth around the sun; physicists now define the second in terms of the fundamental properties of atoms.
It is available from Amazon, typically about (As of earlier time of writing - subject to change.)
![]() | Chemical analysis and synthesis go no farther than to the separation of particles one from another, and to their reunion. No new creation or destruction of matter is within the reach of chemical agency. We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence, as to create or destroy a particle of hydrogen. |
![]() | The history of science has proved that fundamental research is the lifeblood of individual progress and that the ideas that lead to spectacular advances spring from it. |
![]() | I might paraphrase Churchill and say: never have I received so much for so little. [Exemplifying humility, upon accepting the Nobel Prize in Chemistry.] |
Before you look at today's web page, see if you can answer some of these questions about the events that happened on this day. Some of the names are very familiar. Others will likely stump you. Tickle your curiosity with these questions, then check your answers on today's web page. | |
Births | |
![]() | Louis Essen, born 6 Sep 1908, invented the first practical atomic clock. He built a atomic-beam clock utilizing the natural frequencies of an atom that are inherently stable over time and space to greatly increase the accuracy of time-keeping. The atoms of which element were used in Essen's atomic clock? |
![]() | On 6 Sep 1766, John Dalton, a giant in the history of chemistry was born - an English scientist, known as one of the fathers of modern physical science. What was his notable contribution to chemistry? |
Deaths | |
![]() | Sir Frederick Abel (1827-1902) was an English chemist and military explosives specialist who co-invented cordite (1889) to replace gunpowder in weapons What was the advantage of cordite over gunpowder? |
![]() | On 6 Sep 1970, Arthur Herrington died, an American engineer and manufacturer who developed a series of military vehicles. His best known served various functions in World War II, including as a litterbearer, machine gun firing mount, reconnaissance vehicle, pickup truck, front line limousine, ammo bearer, wire-layer and taxi. What was this vehicle? |
Events | |
![]() | On 6 Sep of a certain year, the first British telephone exchange opened in Lombard Street, London. What was the decade of this event? |
![]() | On 6 Sep 1947, the aircraft-carrier Midway became the first U.S. vessel from which a long-range rocket was launched. It was fired from the flight deck from a position at sea several hundred miles of the east coast of the U.S. the rocket travelled about 6 miles. However, the rocket being observed was not American-made. Why was the rocket used for the first U.S. vessel launch not American-made? |
Fast answers for the previous newsletter for September 5: canal rays • Euclid • suicide • anthropology • decade of 1887 • estimated seven miles.

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