Operation Grapple was a series of British nuclear weapons tests carried out in 1957 and 1958 at Malden Island and Christmas Island in what is now Kiribati. Britain had successfully tested an atomic bomb in October 1952, and in July 1954, decided to develop a hydrogen bomb. In the first test, Grapple 1 (pictured), the bomb's yield was below its designed capability. The second, Grapple 2, was the largest ever achieved by a single-stage device. The third, Grapple 3, also had a low yield. A further test, Grapple X, exceeded expectations. Grapple Y, in April 1958, yielded about three megatonnes and remains the most powerful British nuclear weapon ever tested. Much of its yield came from its thermonuclear reaction, making it a true hydrogen bomb, and the United Kingdom became the third nation to possess one. A final series of four tests, Grapple Z, tested techniques for making bombs immune to predetonation by nearby nuclear explosions. (This article is part of a featured topic: Nuclear weapons and the United Kingdom.).

Read more: https://en.wikipedia.org/wiki/Wikipedia:Featured_topics/Nuclear_weapons_and_the_United_Kingdom

_______________________________ Today's selected anniversaries:

1865:

Henry Wirz, the Confederate superintendent of Andersonville Prison, was hanged after a controversial conviction, becoming the only American Civil War soldier executed for war crimes. https://en.wikipedia.org/wiki/Henry_Wirz

1937:

Brazilian president Getúlio Vargas executed a self-coup of his constitutional government, establishing the dictatorial Estado Novo regime. https://en.wikipedia.org/wiki/1937_Brazilian_coup_d%27%C3%A9tat

1958:

Merchant Harry Winston donated the Hope Diamond, the "most famous diamond in the world", to the Smithsonian Institution. https://en.wikipedia.org/wiki/Hope_Diamond

2009:

Ships of the South Korean and North Korean navies skirmished off Daecheong Island in the Yellow Sea. https://en.wikipedia.org/wiki/Daecheong_incident

_____________________________ Wiktionary's word of the day:

sumac: 1. Any of various shrubs or small trees of the genus Rhus and other genera in Anacardiaceae, particularly the elm-leaved sumac, Sicilian sumac, or tanner's sumac (Rhus coriaria). 2. Dried and chopped-up leaves and stems of a plant of the genus Rhus, particularly the tanner's sumac (see sense 1), used for dyeing and tanning leather or for medicinal purposes. 3. A sour spice popular in the Eastern Mediterranean, made from the berries of tanner's sumac. https://en.wiktionary.org/wiki/sumac

___________________________ Wikiquote quote of the day:

The little folk dare anything … And they talks a lot of nonsense. But they talks an awful lot of sense, as well. You listen to 'em at your peril, and you ignore 'em at your peril, too.   --Stardust : Being A Romance Within The Realm of Faerie https://en.wikiquote.org/wiki/Stardust_%28Gaiman_novel%29