Another example indicating an error which can not be detected by inspection is shown in figure 84, _C_. In glyphs 1 and 2 appears the date 8 Eznab 16 Uo (compare glyph 1 with fig. 16, _c'_, and glyph 2 with fig. 19, _b, c_). In glyph 3 follows a number consisting of 17 kins and 4 uinals (4.17). Finally, in glyphs 4 and 5 is recorded the date 2 Men 13 Yaxkin (compare glyph 4 with fig. 16, _y_, and glyph 5 with fig. 19, _k, l_). This has every appearance of being a Secondary Series, of which 8 Eznab 16 Uo is the starting point, 4.17, the number to be counted, and 2 Men 13 Yaxkin the terminal date. Reducing 4.17 to units of the first order and counting it forward from the starting point indicated, the terminal date reached will be 1 Men 13 Yaxkin. This differs from the terminal date recorded in glyphs 4 and 5 in having a day coefficient of 1 instead of 2. Since this involves but a very slight change in the original text, we are probably justified in assuming; that the day coefficient in glyph 4 should have been 1 instead of 2 as recorded. One more example will suffice to show the kind of errors usually encountered in the inscriptions. In plate 26 is figured the Initial Series from Stela N at Copan. The introducing glyph appears in A1 and is followed by the Initial-series number 9.16.10.0.0 in A2-A6, all the coefficients of which are unusually clear. Reducing this to units of the first order and solving for the terminal date, the date reached will be 1 Ahau 3 Zip. This agrees with the terminal date recorded in A7-A15 except for the month coefficient, which is 8 in the text instead of 3, as determined by calculation. Assuming that the date recorded is correct and that the error is in the coefficient of the period glyphs the next step is to find the positions in Cycle 9 at which the date 1 Ahau 8 Zip occurred. Referring to Goodman's Tables, these will be found to be: 9. 0. 8.11.0 1 Ahau 8 Zip 9. 3. 1. 6.0 1 Ahau 8 Zip 9. 5.14. 1.0 1 Ahau 8 Zip 9. 8. 6.14.0 1 Ahau 8 Zip 9.10.19. 9.0 1 Ahau 8 Zip 9.13.12. 4.0 1 Ahau 8 Zip 9.16. 4.17.0 1 Ahau 8 Zip 9.18.17.12.0 1 Ahau 8 Zip [Illustration: INITIAL SERIES ON STELA N, COPAN, SHOWING ERROR IN MONTH COEFFICIENT]