Page I-89, "on opposite sides of the central line": this should be read "on opposite sides of the central lines" (both horizontal and vertical).
Page I-130, mens’ tears: as printed in the source document.
Page I-131, An Illusion of Type: the phenomenon described may not work with every font. Therefore the right-side-up and upside-down text lines have been inserted as an additional illustration.
Page I-136, For the Children, last sentence: the opposite is true: If this is an even quantity the coins or sweets in the right hand are odd, and in the left even; if it is odd the contrary is the case.
Page II-130, number 81: some words were misprinted or missing altogether; these have been added based on the context: ... the man [fe]ll sick ...; [Ho]w ought his estate ...; and ... to [the] widow, son and daughter.
Page II-148, Notable Chronogram: IAVDES should have read LAVDES, which would result in the year 1894 (when the organ was blessed).
Page II-176, Solution LXXX: The positions of the dots are indicated in the text only, not in the diagram.
Page II-204, Solution 65, 12 + 1⁄2 = 13⁄2: the calculation only works if the 12 were replaced with 12⁄2 (or 6), which would be in accordance with the description.
Page II-206, Solution 77: two and twenty pence should probably read two and twenty pence.
Page III-3 and III-111, No. III: The illustration in the question is not the same as the one in the answer.