The annotation following Letter Number 20, (McKeithan's #24) claims that this letter was used in Volume II Chapter XIII. I believe this is actually a typo, the correct chapter would be VIII, chapter 35 of the full volume or chapter 8 of the 2 volume set.
The Innocents Abroad - Chapter 35
Far-Away Moses is rather an interesting individual. I did a search on him and found this:
from Making a Place in the World: Jews and the Holy Land at World's Fairs by Barbara Kirshenblatt-Gimblett
" This difficulty in no way restrained the claims made for Jewish racial purity and for "Oriental" Jews as the purest examples of the Jewish racial type. Consider the caption for Far-Away-Moses:
The Jews are the most remarkable of all races. No other people can boast a lineage so ancient and so unbroken. The historian Freeman says: "They are very nearly, if not absolutely, a pure race in a sense in which no other race is pure." Their early history constitutes body of sacred writings which, considered as literature alone, stands unequalled.... The above portrait is another illustration of the persistence of the Jewish type. This man, who rejoices in the expressive sobriquet of Far-Away-Moses, is the descendant of Jews who were driven from Spain by Queen Isabella. He is fifty-five years old and resides in Constantinople. He speaks many languages and is a noted dragoman. He has been immortalized by Mark Twain, whom he had the honor of conducting through the Holy Land.
Far-Away-Moses, as it turns out, was one of the partners in the company that held the concession for the Turkish village--he was none other than Harry R. Mandil, one of the two American partners. He was also the model for Semite head in the ethnological series of thirty-three races that adorn the keystones above the windows on the first floor of the Library of Congress. Had Mandil appeared clean shaven in a business suit as an American citizen would he have been chosen as the model for the Semite head?