At all events, the conception of the seven or eight climates did not disappear but at a very early period, whether by Ptolemy or not, was correlated with the Ptolemaic parallels.[1111] That is to say, certain of Ptolemy’s parallels were used to designate the imaginary lines marking the centers and bounds of the climates. This practice was adopted by the Arabs and from them transferred to the knowledge of the Christian West in various astronomical treatises. Among the Latin manuscripts of the _Toledo Tables_,[1112] for instance, there are series of astronomical tables for each of the seven climates, according to which the climates occupy the space between latitude 16° N., with a longest day of thirteen hours, and 48° N., with a longest day of sixteen hours. The length of the longest day and the latitude are given for each parallel that bounds the climates. Except that Ptolemy notes minutes as well as degrees and in the _Toledo Tables_ the minutes have in most cases been omitted, the figures correspond essentially with those of the _Almagest_ and _Geography_. Thus: Ptolemy’s eleventh parallel according to the _Almagest_ (or tenth according to the _Geography_) has a longest day of fourteen and a half hours and is at latitude 36°. In the _Tables_ the southern edge of the fourth climate likewise has a longest day of fourteen and a half hours and is at latitude 36°. Again, in John of Seville’s translation of Al-Farghānī’s _Astronomy_[1113] and in the _De sphaera_[1114] of John of Holywood, who had borrowed from Al-Farghānī in this matter, we find a similar correlation. In both cases the figures of latitude correspond essentially, though with slight divergences in detail, to those of Ptolemy. The boundaries of each climate, however, have here been displaced by one parallel to the south of the parallels used in the _Toledo Tables_ and those which we may presume were the Ptolemaic boundaries of the climates.[1115] The table, Figure 11 (in the Notes to Ch. X), gives some idea of the relative degree of accuracy of these figures as they were employed in the West during the Middle Ages. But just as in the case of other figures for latitude and longitude, as we shall shortly have occasion to see, this material was not utilized for geographical purposes during our age. GEOGRAPHICAL COÖRDINATES