Mark 21 nuclear bomb
The Mark 21 nuclear bomb was a United States nuclear gravity bomb first produced in 1955. It was based on the TX-21 "Shrimp" prototype that had been detonated during the Castle Bravo test in March 1954. While most of the Operation Castle tests were intended to evaluate weapons intended for immediate stockpile, or which were already available for use as part of the Emergency Capability Program, Castle Bravo was intended to test a design which would drastically reduce the size and costs of the first generation of air-droppable atomic weapons (the Mk 14, Mk 17 & Mk 24). At long, in diameter, and weighing , the Mk-21 was half the length and one-third the weight of the Mk-17/24 weapons it replaced. Its minimum yield was specified at four megatons.
Giovanni Battista Trevano
Trevano started working in Poland around 1600. He was one of the team of architects and craftsmen who rebuilt the Royal Castle in Warsaw, on the basis of the old Gothic castle of the Masovian princes, which had already been completely remodeled by Italian architects in the second half of the sixteenth century. New work was undertaken in the years 1598-1619. He was not alone in this project: Giacomo Rodondo, Paolo del Corte and Mateo Castelli were all involved in remaking the castle into a new Baroque structure, on its imposing site along the bank of the river Vistula. The castle, much altered over the years, was bombed and dynamited by the Nazis as a symbol of Polish culture and was rebuilt in the years 1971–1988 as a national monument.