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General
In 1795, France adopted by law, the metre as the unit of length and the base of the metric system. Since there had been no uniformity of French weights and measures prior to the Revolution, the Academy of Sciences had been charged on 8 May 1790 to organise a better system. Delambre and Méchain measured an arc of the meridian from Dunkirk to Barcelona, so that the metre could be defined as one ten-millionth part of the distance between the poles and the equator.
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Earth Science
In 1845, the first surviving daguerrotype photograph showing details of the sun was taken by French physicists Armand Fizeau and Léon Foucault. The 5-inch (12 cm) image had an exposure of 1/60 second, and showed the umbra/penumbra structure of several sunspots, as well as limb darkening. The photographic process was new: Daguerre perfected the daguerreotype only a few years earlier, in 1838. Fizeau and Foucault had been collaborating with their own experiments on the process since 1839. Fizeau had much improved the durability of a daguerreotype image with a treatment, published in Aug 1840, using a solution of chloride of gold mixed with hypo-sulphite of soda, then heated over a spirit-lamp.
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Biology
In 1953, the journal Nature published a paper with this date from Francis Crick and James Watson, titled Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid, in which they described a double helix structure for DNA. The diagram published with the caper was captioned, "The figure is purely diagrammatic. The two ribbons symbolize the phosphate-sugar chains, and the horizontal rods the pairs of bases holding the chains together. The vertical line marks the fibre axis."
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Chemistry
In 1944, the first synthetic quinine was produced by Dr. Robert Burns Woodward (on his birthday) and Dr. William von Eggers Doering at the Converse Memorial Laboratory, Harvard University, Cambridge, Mass. Quinine, an anti-malarial drug, is an organic chemical with the formula C20H24N2O2.
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Physics
In 1886, German scientist, Dr. Carl Gassner, was issued a German patent (No. 37,758) for the first "dry" cell, which used zinc as its primary ingredient. He encased the cell chemicals in a sealed zinc container. Gassner's battery was much like the carbon-zinc, general-purpose batteries on the market today. Gassner also patented his invention in Austria, Belgium, England, France and Hungary in the same year. A U.S. patent was issued to Gassner in 1887 (No. 373,064). In America, by 1896, the Nation Carbide Company, later Union Carbide and Eveready, produced the first consumer dry cell battery. Two years later, the company made the first D cell. Combined with the invention of incandescent light bulbs, portable electric lights became common.
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And here is a quote for you and your students to ponder and discuss.
I think of a hero as someone who understands the degree of responsibility that comes with his freedom. - Bob Dylan
