From ec84b45ba4a48bd4b50c98fdeffa13f836842be7 Mon Sep 17 00:00:00 2001 From: Ben Harris Date: Sat, 11 Feb 2023 19:35:32 +0000 Subject: [PATCH] Mention how old the 15-puzzle is For most puzzles, the manual tries to at least mention its origin. Wikipedia suggests that the precise inventor of the 15-puzzle is a bit uncertain, but US patent number 207124 definitely describes it in 1878, so "dates from the 1870s" seems pretty solid. --- puzzles.but | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/puzzles.but b/puzzles.but index 9791ead..d56d26c 100644 --- a/puzzles.but +++ b/puzzles.but @@ -601,7 +601,8 @@ respectively. \cfg{winhelp-topic}{games.fifteen} The old ones are the best: this is the good old \q{\i{15-puzzle}} -with sliding tiles. You have a 4\by\.4 square grid; 15 squares +with sliding tiles, which dates from the 1870s. +You have a 4\by\.4 square grid; 15 squares contain numbered tiles, and the sixteenth is empty. Your move is to choose a tile next to the empty space, and slide it into the space. The aim is to end up with the tiles in numerical order, with the