Wikipedia:Main Page history/2022 January 3b

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Title page of Recollections of Full Years by Helen Taft
Title page of Recollections of Full Years by Helen Taft

The Personal Memoirs of Julia Dent Grant in the 1890s after the death of her husband, Ulysses S. Grant, but she never found a suitable publisher for them before her death in 1902. Helen Taft was the first to have memoirs (title page pictured) published during her lifetime, in 1914. Memoirs by presidential spouses were uncommon until the 1970s; most first ladies have written and published at least one memoir about their life since Betty Ford's publication of her first memoir in the late 1970s. (Full list...
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Thin section

In optical mineralogy and petrography, a thin section is a thin slice of a rock, mineral, soil, pottery, bones, or even metal sample, prepared in a laboratory, for use with a polarizing petrographic microscope, electron microscope and electron microprobe. A thin sliver of rock is cut from the sample with a diamond saw and ground optically flat. It is then mounted on a glass slide and then ground smooth using progressively finer abrasive grit until the sample is only 30 micrometres (0.0012 in) thick. This image shows a thin section of Siilinjärvi apatite ore from Finland in cross-polarized transmitted light; the specimen depicted here is approximately 36.6 mm (1.44 in) wide by 20 mm (0.79 in) high.

Photograph credit: Kallerna