24 The Book of Indoor and Outdoor Games
Two words are chosen containing the same number of letters, which are written, the one at the top, and the other at the bottom of the page. The puzzle consists in the merging of the one in the other by the interposition of other words, each of which, by the change of a single letter, shall form a link contributing to the result. The easiest doublets are made where the vowels and consonants correspond in number and position in both words.
The game is taken from a little volume by Lewis Carroll, the famous author of "Alice in Wonderland," called "Doublets, a Word Puzzler," in which the following rules are given:
"The words given to be linked together constitute a Doublet. The interposed words are the links, and the entire series a chain.
"Each word in the chain must be formed from the preceding word by changing one letter in it and one only. The substituted letter must occupy the same place in the word so formed which the discarded letter occupied in the preceding word, and all the other letters must retain their places.
"The score for the game is: the same number of marks will be apportioned to each doublet as equal the number of letters in the two words given. For example, for "head and tail" the number of marks obtainable would be eight; and this maximum will be obtained by the competitor who makes the change with the least number of changes. A mark in this case would be deducted for every link used beyond four. If it be assumed that in this instance the change cannot be made with less than four links, then those who complete it with four links