Long transposal pairs, especially those in which the letters of one word must be thoroughly rearranged to form the other, have always fascinated logologists; in the February 1976 issue of Word Ways, I presented a list of well-mixed transposal pairs of 13 letters or more. A well-mixed transposal pair is defined as one in which at most three consecutive letters in one word appear in the other; for example, both words of the 17-letter transposal pair baSIPaRACHromATin - marSIPobRAnCHiATa contain the trigram SIP and the bigrams CH, RA and AT, but no others. This transposal pair, discovered by Charles Holding and first appearing in The Enigma in 1972, is the longest well-mixed one known; in fact, the February 1976 article and the May 1976 Colloquy listed no 16-letter well-mixed pairs, four 15-letter well-mixed pairs, and eleven 14-letter well-mixed pairs. Since then, John Edward Ogden discovered in 1978 the 16-letter well-mixed pair HEmatocrySTaLLin - tHErmonaSTicaLLy, with three bigrams HE, ST and LL; furthermore, a well-known 15-letter well-mixed pair can be pluralized to obtain megachiropteRAns - cinematogRAphers.
Eckler, A. Ross
"Sixteen-Letter Transposal Pairs,"
Word Ways: Vol. 14
, Article 21.
Available at: https://digitalcommons.butler.edu/wordways/vol14/iss1/21