Some of the most curious chapters of the 1948 War of Independence involve a peculiar weapon known to every Israeli as the Davidka. In 1948, the newly-minted, poorly-supplied, disorganized and undermanned Israeli forces faced seven Arab armies and an unknown number of local irregular forces, a power whose stated goal was to drive the Jews into the sea. Lacking sufficient arms, improvisation became the order of the day among the Israelis; it was this improvisation that led to the development of the Davidka.
It was nominally a mortar, although its shell was wider by far than its barrel, and instead of explosives it was packed with whatever metal ballast the soldiers who were firing it had on hand. This, combined with its gross inaccuracy, made the Davidka more of a specialized popgun than a weapon of destruction – but the "pop" it made was so impressive that the firing of the Davidka led to panicked retreat of more than one Arab force.
A rumor spread among the Arab armies that Jewish American scientists had given their Israeli counterparts the knowledge to manufacture the atom bomb, and it was assumed that the humble Davidka with its furious roar was launching nuclear payloads. This convenient misinformation led to the Palmach's victory in Tzfat, and also contributed to the battle for Jerusalem.
The Davidka used in the Jerusalem campaign has been enshrined in a stone monument at the center of the aptly named Kikar Davidka, a public square on Jaffa Road just down the street from the entrance to the Machane Yehuda market. It's worth it to stop by and see the tiny mortar that, armed with little more than a big bang, helped found the State of Israel.
לכיכר הדוידקה בעברית לחץ כאן