block and tackle vs snap fastener

block and tackle

noun
  • The underwear combination of stockings worn with a suspender belt. 

  • A system in which a rope, cable, or chain (the tackle) is passed over pulleys enclosed in two (or rarely more) blocks, one fixed and one attached to a load, which is used to gain mechanical advantage to lift or pull heavy loads. 

snap fastener

noun
  • a pair of male/female interlocking disks used to fasten a piece of clothing in place of buttons 

How often have the words block and tackle and snap fastener occurred in a corpus of books? (source: Google Ngram Viewer )