by and by vs promptly

by and by

adv
  • After a short time. 

  • After an indefinite period. 

noun
  • Heaven; the hereafter. Usually preceded with "the sweet." 

promptly

adv
  • In prompt manner; both soon and quickly. 

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