packet boat vs shuttle

packet boat

noun
  • A boat that carried mail, cargo, and, in later years, some passengers along a regularly scheduled route up and down a river or canal. 

  • A boat specifically designed to provide transportation to passengers on a regular schedule up and down a river or canal. 

  • An ocean-going ship chartered by the government to carry the mail and official communications. 

shuttle

noun
  • A transport service (such as a bus or train) that goes back and forth between two or more places. 

  • The sliding thread holder in a sewing machine, which carries the lower thread through a loop of the upper thread, to make a lock stitch. 

  • A tool used to carry the woof back and forth between the warp threads on a loom. 

  • A shutter, as for a channel for molten metal. 

  • Any other item that moves repeatedly back and forth between two positions, possibly transporting something else with it between those points (such as, in chemistry, a molecular shuttle). 

  • A shuttlecock. 

  • Such a transport vehicle; a shuttle bus; a space shuttle. 

verb
  • To transport by shuttle or by means of a shuttle service. 

  • To go back and forth between two places. 

How often have the words packet boat and shuttle occurred in a corpus of books? (source: Google Ngram Viewer )