XVI.] HIS ACCOUNT OF BRITAIN. 347
closely with the reality. The gradual southward slope of the
southern coast as it proceeds from east to west clearly appears.
The most important inlets—the Bristol Channel, the Solway Firth
and that of Clyde, above all the marked indentation produced by
the Moray Firth—are all strikingly delineated. The same thing
is true of the promontories. The two separate capes at the south-
western angle, the Lizard and the Land's End, St David's Head and
the extremity of Cardiganshire in Wales, and the Mull of Galloway
and that of Cantire on the western side of Scotland, are carefully
distinguished. The general accuracy which is thus apparent
makes it the more surprising that in one important particular,
namely the position of Scotland relatively to England, Erroneous
Ptolemy's map should be extravagantly in error. Position of
For, whereas the southern part of the island as far
as the line of the Solway Firth is correctly orientated, the northern
portion is twisted round towards the east, so that the mouth of the
Clyde, instead of lying to the westward of the Firth of Forth, is due
north of it, and the farthest extremity of the country, the promon-
tory of Orcas, instead of pointing northward faces due east. On
the same principle the western and eastern coasts of Scotland are
called by Ptolemy in this part of his tables the northern and
southern coasts. It is difficult to account for this extraordinary
mistake. The latest, and at the same time the most possii,ie
probable explanation of it is that of Mr Henry Explanation of
Bradley, who would attribute it, not to defective
information, but to an error in the construction of the map.
Either Ptolemy or one of his predecessors, he suggests, had before
him three sectional maps, representing severally the countries
which we call England, Scotland, and Ireland, and drawn approxi-
mately to scale, but without meridians or parallels. It was, no
doubt, then, as now, usual for a map to be enclosed in a rectangular
frame, with sides towards the four cardinal points. In fitting the,
three maps together, Ptolemy (or his predecessor) fell into the
mistake of turning the oblong map of Scotland the wrong way.
Mr Bradley further points out, in explanation of the origin of this
mistake on Ptolemy's part, that he had assigned to Ireland a
latitude so much too high, that if he had given to the map of