Historical observations
This winter I plan to finish creating a course on Ampacity. I have gathered some very outstanding papers from Neher-McGrath, Samuel Rosch, Matt Brown, Donald Simmons, Peter Pollack, and John Caloggero dating from 1932 to 1988. I obtained most of these from the Engineering Societies Library that used to exist in New York City where you could order just about any paper you needed using the telephone and a fax machine. Unfortunately this service is no longer in business and now one has to search through the Journals at the nearest University library. Many of the NEC rules come from such papers and it is very interesting to find the actual research and analysis that was done so many years ago. Many times we do not have the time to perform this research and the history of subjects such as ampacity of conductors stays buried in the journals of long ago. The original heat transfer equation used to develop ampacity tables comes from the work of Jean Baptiste Joseph Fourier (1768 - 1830).
Fourier was born in Auxerre, France, the ninth of twelve children. He trained for the priesthood, but spent much of his life teaching mathematics at French universities, principally the École Polytechnique. He was active in the French Revolution, and his activity twice resulted in imprisonment and a potential visit to the guillotine. From 1798 to 1801, he acted as Napoleon's scientific adviser and sometime administrator in the Egyptian campaign. From 1804 to 1807, he served as prefect of Grenoble, a post he reluctantly accepted because the appointment was made by Napoleon. He was elected to the Académie des Sciences in 1817, and served as its secretary.
(In 1807, Fourier submitted a paper on heat transfer to the Institute of France.) The paper caused great controversy among the examiners . . . Fourier sent in papers in 1808 and 1809 to meet criticisms, and eventually a prize problem on heat diffusion was proposed by the Institut de France for January 1812, to which he submitted a considerably revised and extended version of the 1807 paper. . . He won the prize; but publication was still delayed. So he began a third version of his work in the form of a book, which eventually appeared as Théorie analytique de la chaleur in 1822. The prize paper also appeared—unchanged—in two parts . . . in 1824 and 1826.
On a more current side....
State of Washington's L and I has issued a special edition of Electrical Currents describing the Class B electrical permitting system. It can be found at by clicking here
If you work in Washington in the electrical trades you should subscribe to the Electrical Currents newsletter that will be sent to you by email at no extra cost.
Fourier was born in Auxerre, France, the ninth of twelve children. He trained for the priesthood, but spent much of his life teaching mathematics at French universities, principally the École Polytechnique. He was active in the French Revolution, and his activity twice resulted in imprisonment and a potential visit to the guillotine. From 1798 to 1801, he acted as Napoleon's scientific adviser and sometime administrator in the Egyptian campaign. From 1804 to 1807, he served as prefect of Grenoble, a post he reluctantly accepted because the appointment was made by Napoleon. He was elected to the Académie des Sciences in 1817, and served as its secretary.
(In 1807, Fourier submitted a paper on heat transfer to the Institute of France.) The paper caused great controversy among the examiners . . . Fourier sent in papers in 1808 and 1809 to meet criticisms, and eventually a prize problem on heat diffusion was proposed by the Institut de France for January 1812, to which he submitted a considerably revised and extended version of the 1807 paper. . . He won the prize; but publication was still delayed. So he began a third version of his work in the form of a book, which eventually appeared as Théorie analytique de la chaleur in 1822. The prize paper also appeared—unchanged—in two parts . . . in 1824 and 1826.
On a more current side....
State of Washington's L and I has issued a special edition of Electrical Currents describing the Class B electrical permitting system. It can be found at by clicking here
If you work in Washington in the electrical trades you should subscribe to the Electrical Currents newsletter that will be sent to you by email at no extra cost.
posted by Gerald Newton at 3:56 AM
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