Northern Ladle vs Plough

Northern Ladle

name
  • A bright circumpolar asterism of the northern sky, said to resemble a ladle. It is part of the constellation Ursa Major and includes the stars Alkaid, Mizar, Alioth, Megrez, Dubhe, Merak, and Phecda. 

Plough

name
  • The brightest seven stars of the constellation Ursa Major. They are Alkaid, Mizar, Alioth, Megrez, Dubhe, Merak, and Phecda. 

  • A surname. 

How often have the words Northern Ladle and Plough occurred in a corpus of books? (source: Google Ngram Viewer )