Weather map map using his own system of symbols, thereby creating the world's first weather map. He used his map to prove that air circulated clockwise around areas of high pressure; he coined the term 'anticyclone' to describe the phenomenon. He was also instrumental in publishing the first weather map in a newspaper, for which he modified the pantograph (an instrument for copying drawings) to inscribe the map onto printing blocks. "The Times" began printing weather maps using these methods with data from the Meteorological Office. The introduction of country-wide weather maps required the existence of national telegraph networks so that data
Word ladder the "start word" (synonymous, antonymous, semantic...). This was also the way the game was originally devised by Lewis Carroll when it first appeared in "Vanity Fair". Some variations also allow the player to add or remove letters, and to rearrange the same letters into a different order (an anagram). Donald Knuth used a computer to study word ladders of five-letter words. He believed that three-letter word ladders were too easy (although Lewis Carroll found six steps were required for APE to evolve into MAN), and that six-letter word ladders were less interesting, since relatively few pairs of six-letter words could