Chapter X: The Astronomical Geography of the Known World

Footnote 1095:

_Etym._, XIV, 6.

Footnote 1096:

_De imag. mundi_, I, 11.

Footnote 1097:

_Im. du monde_, II, 2.

Footnote 1098:

_Otia imper._, vol. i, p. 911.

Footnote 1099:

_De sphaera_, 3.

Footnote 1100:

_De imag. mundi_, I, 31.

Footnote 1101:

_Collectanea_, 22.

Footnote 1102:

_Etym._, XIV, 6.

Footnote 1103:

_Top. Hiber._, II, 17.

Footnote 1104:

See above, p. 23.

Footnote 1105:

_Hist. nat._, VI, 33–34.

Footnote 1106:

_De nupt. Phil. et Merc._, VIII, 876.

Footnote 1107:

_Almagest_, II, 6.

Footnote 1108:

_Geogr._, I, 23.

Footnote 1109:

The relation between the parallels as given in the _Almagest_, _loc.
cit._ and in the _Geography_, _loc. cit._, are shown graphically in
the adjoining table (Fig. 11, cols. I and II). In the text of the
_Almagest_ the parallels are not specifically named beyond the
twenty-sixth. Each paragraph, however, is numbered to correspond to
the parallel which it describes through the thirty-eighth. The
thirty-ninth paragraph describes conditions at the pole.

Footnote 1110:

See Fischer, _Ptolemäus und Agathodämon_, 1916, pp. 89–93.

Footnote 1111:

On the famous Vatopedi manuscript map of the world ascribed to
Agathodaemon by Fischer but, as Fischer claims, directly based upon
material furnished by Ptolemy, the boundaries of the climates are
expressly defined in relation to Ptolemy’s parallels, as set forth in
the _Geography_. The first climate begins with the parallel of Meroë,
latitude 16°25′N., and extends to that of Syene, 23°50′N., there being
a difference of half an hour between the length of the longest day at
its northern and at its southern edge. The other six climates follow
as shown on Figure 11, col. III. The same correlation is made in the
anonymous Greek treatise Διάγνωσις ἐν ἐπιτομῇ τῆς ἐν τῇ σφαίρᾳ
γεωγραφίας in: Müller, _Geogr. graeci min._, 1882, vol. ii, pp.
491–493. See Fischer, _op. cit._, pp. 90–91. See Figure 11, cols. III
and IV.

It may be added that in a work entitled _Preceptum canonis Ptolemei_,
preserved in Chartres, Bibliothèque Publique, MS. No. 214, fol. 1ro.,
and dating perhaps from the sixth century, the writer found a
description of the division of the world in seven climates. No mention
is made of the parallels by number, but the boundaries of the
climates, as there defined and as is shown on Figure 11, col. V,
correspond to the figures for latitude assigned to the fifth, seventh,
ninth, eleventh, thirteenth, fifteenth, and seventeenth parallels of
Ptolemy’s _Almagest_.

FIG. 11 (in two sections)—Comparative diagram of certain parallels of
latitude and of the _climata_ according to various ancient and
medieval geographers. For explanation see the text, pp. 242–243, and
notes 15, 17, 18, and 21 of this chapter.
]

Footnote 1112:

The figures as given in Bibliothèque Nationale MSS., fonds latin, no.
16658, fol. 50ff., are shown in Figure 11, col. VI.

Footnote 1113:

_Rudimenta astronomica_, Nuremberg edit., 1537, fol. 8vo.

Footnote 1114:

_De sphaera_, 3. After giving a brief definition of the climates, John
says: “Dicitur autem clima tantum spacium per quantum sensibiliter
variatur horologium.” In practice, this was always taken to be a
difference of a half hour up to and including the sixth climate.

Footnote 1115:

The boundaries of Al-Farghānī’s and John of Holywood’s climates are
one parallel south of those indicated in the various works referred to
in note 17, p. 453, above, and those of the _Toledo Tables_; that is
to say, the centers of the former are at the parallels of the northern
borders of the latter (see Fig. 11, col. VII). According to
Al-Khwārizmī, the figures for the parallels bounding the climates
appear to have been derived from the _Almagest_; Al-Khwārizmī’s second
climate, however, corresponds to the first climate of Agathodaemon’s
map and of the other works derived from Ptolemy (see above, p. 453,
note 17, and Fig. 11, cols. III-VI). The third climate of Al-Khwārizmī
corresponds to the second climate in the works derived from Ptolemy,
and so on. See Fischer, _op. cit._, p. 92, and footnotes 1 and 2. See
Figure 11, col. VIII.

Footnote 1116:

This subject has been discussed by me in greater detail in: J. K.
Wright, _Knowledge of Latitudes and Longitudes_, 1923.

Footnote 1117:

Bibliothèque Nationale MSS., fonds latin, no. 14704, fol. 119vo. At
the time of the publication of the article referred to in the
preceding note, the writer was not aware of Professor Haskins’
discovery of the name of the author of the _Marseilles Tables_ (see
Haskins, _Studies_, 1924, pp. 96–97).

Footnote 1118:

See, for example, Bibliothèque Nationale MSS., fonds latin, nos. 7198,
fol. 90ro., 7406, fol. 58vo., 7421, fol. 203vo., 16211, fol. 93vo.,
16658, fol. 113ro.

Footnote 1119:

J. K. Wright, _op. cit._, pp. 84–85.

Footnote 1120:

See above, p. 86.

Footnote 1121:

J. K. Wright, _op. cit._, pp. 91–96.

Footnote 1122:

_ibid._, pp. 77–84.

Footnote 1123:

For texts illustrating this see Haskins, _Reception_, 1915, p. 57; the
same, _Studies_, 1924, pp. 114–115. See also Peter Alphonsi,
_Dialogus_, I, in: Migne, _Pat. lat._, vol. clvii, cols. 543–547.

Footnote 1124:

See J. K. Wright, _op. cit._, p. 85.

Footnote 1125:

_Theorica planetarum_, Renner’s edit., fourth page before _explicit_.
See also Bibliothèque Nationale MSS., fonds latin, no. 7421, fol. 133.

Footnote 1126:

See J. K. Wright, _op. cit._, pp. 91–96, for discussion of the
interpretation of these figures. In Figure 12 the circles show the
relative positions of certain points in Europe as they actually are;
the stars show them as given in the tables and referred to the
meridian of Marseilles. It will readily be seen that the relative
longitudes of all the points except London and Toledo are remarkably
accurate when we consider the rough means of calculation at the
disposal of twelfth- and thirteenth-century observers. London and
Toledo are placed accurately in relation to each other though far
astray in relation to Marseilles, probably as a result of a single
initial error in the estimation of the number of degrees between the
meridian of Toledo and that of some intermediate station (perhaps
Marseilles) from which the positions of the remaining stations were
calculated. The highly erroneous latitudes of Toulouse, Florence, and
Naples are probably attributable to clerical errors. For a fuller
discussion of this map see work cited, p. 95.

FIG. 12—Map showing the relative positions of certain points in Europe
as indicated in astronomical tables of the twelfth and early
thirteenth centuries. In the original tables a consistent error
appears in the longitudes of all the cities in Italy. This has been
corrected as discussed in the work cited in note 32 above.
]

NOTES