Of these items 22 had the best authority, and 30 and 7 were independent records or traditions (as we know from Muirchu and Tírechán). The problem is therefore reduced to discovering the origin of the 61 or 60 years during which the apostle is wrongly supposed to have taught. That it was due to a misinterpretation and not to a deliberate invention, there can, I think, be no question. A list of the Armagh succession in the Book of Leinster (printed in Stokes, _Trip._ pp. 542 _sqq._) supplies a hint which suggests an explanation of the error. The first entry is— Patrick: 58 years _from the coming of Patrick to Ireland_ till his death. The fact that a period of 58 years is given here instead of the usual number (493-433/2) is remarkable. Now if we count back 58 years from the _true_ date of Patrick’s death, 461, we reach the year 403-404, which was in the close vicinity of the year in which, as we saw, he was probably taken into slavery. Hence it seems probable that in an early record it was stated correctly that 58 years elapsed between the coming of Patrick to Ireland, meaning his _first_ coming as a slave, and his death, and that this notice was misinterpreted by subsequent computators who referred it to his _second_ coming as a teacher. They computed: 22 + 7 (_ambulauit_) + 30 (_legit_) + 58 (_docuit_) = 117. An age so close to 120 could hardly fail to suggest Moses; the figures clamoured for a slight manipulation, and the means adopted was to increase the last period from 58 to 61. Thus the date of the death was determined: 432 + 61 = 493. By this computation the coming to Ireland divided the whole life into two almost equal parts (59 + 61), which would naturally come to be described in round numbers as each 60 years. This probably led to the alternative date for the obit given in the _Ann. Ult._ 492 (= 432 + 60). The computation which established 120 years for the age and A.D. 493 for the year of the death, thus involving 61 years for the Irish period, was triumphant and became authoritative. But the computations quoted above from the _Liber Armachanus_ show that other theories had been propounded based on the addition of items. In the _Vita Tertia_ the age is given as 132. This figure seems to have been obtained by substituting 72 instead of the (round) 60 for the last item in the sum; this is suggested by the fact that in the second computation in the _Liber Armachanus_ the last item is _septuaginta duo annos docuit_, though the total 120 (119) is secured by erroneous dates for the captivity. What is the origin of this number 72? It must have come down in some form, it must have represented something, when, in order to do justice to it, one computator felt compelled to raise the Mosaic 120 to 132, and another, though holding fast to 120, modified the authentic dates of the captivity. I suggest that this number 72 represents an old and correct record of Patrick’s age at the time of his death. 21. _Professor Zimmer’s Theory_