 Richard S. Pearle & Co. of Chicago photoengraved some sets in 1891, and added 3 volumes of "American Revisions and additions," the first 2 in 1891 and the third in 1892.In 1893 they published sets with volumes 1–24 from the original Britannica, the 3 "American" volumes 25–27, and the index as Vol.28.