 Complete the following phrase:  At the Battle of Leuthen in 1757, Fredericks nascent mobile artillery kept pace with the rapidly-moving infantry and laid devastating barrages upon the Austrian lines. Officially, Fredericks first horse artillery detachment, created through a Cabinet Order in April 1759, included six 6pound guns, referred to as light guns. The types of guns might include 6pound guns, a 7pound howitzer, and 3pound guns. The horse artillery was lost at 