<P> According to the 18th - century historian Ludovico Antonio Muratori, rockets were used in the war between the Republics of Genoa and Venice at Chioggia in 1380 . It is uncertain whether Muratori was correct in his interpretation, as the reference might also have been to bombard, but Muratori is the source for the widespread claim that the earliest recorded European use of rocket artillery dates to 1380 . Konrad Kyeser described rockets in his famous military treatise Bellifortis around 1405 . Kyeser describes three types of rockets, swimming, free flying and captive . </P> <P> Joanes de Fontana in Bellicorum instrumentorum liber (c. 1420) described flying rockets in the shape of doves, running rockets in the shape of hares, and a large car driven by three rockets, as well as a large rocket torpedo with the head of a sea monster . </P> <P> In the mid-16th century, Conrad Haas wrote a book that described rocket technology that combined fireworks and weapons technologies . This manuscript was discovered in 1961, in the Sibiu public records (Sibiu public records Varia II 374). His work dealt with the theory of motion of multi-stage rockets, different fuel mixtures using liquid fuel, and introduced delta - shape fins and bell - shaped nozzles . </P> <P> The name Rocket comes from the Italian rocchetta, meaning "bobbin" or "little spindle", given due to the similarity in shape to the bobbin or spool used to hold the thread to be fed to a spinning wheel . The Italian term was adopted into German in the mid 16th century, by Leonhard Fronsperger in a book on rocket artillery published in 1557, using the spelling rogete, and by Conrad Haas as rackette; adoption into English dates to ca . 1610 . Johann Schmidlap, a German fireworks maker, is believed to have experimented with staging in 1590 . </P>

Who discovered that the accuracy of early rockets could be improved by spinning them