Pennsylvania vs Rockhill Furnace

Pennsylvania

name
  • A state of the United States. Capital: Harrisburg; largest city: Philadelphia. 

  • An unincorporated community in Mobile County, Alabama, United States. 

  • A suburb of Exeter, Devon, England (OS grid ref SX9294). 

  • A hamlet in Cold Ashton parish, South Gloucestershire, Gloucestershire, England (OS grid ref ST7473). 

  • The first, and historically largest, now defunct US railroad, a hallmark of the industrial age. 

Rockhill Furnace

name
  • Synonym of Rockhill, Huntingdon County, Pennsylvania. 

How often have the words Pennsylvania and Rockhill Furnace occurred in a corpus of books? (source: Google Ngram Viewer )