_Propontis_, is in no part of it less than three hundred Paces broad, nor above seven hundred Paces long. The Plain of the Valley which encloses the Foot of the Hill Westward, and which divides the seventh Hill from the _Promontory_, reaching from the Shore of the _Propontis_, where the Walls are not encompassed by the Sea, is almost upon a Level, and is in every part of it five hundred Paces in Breadth. The three Hills I have mention’d, may very properly be called the _Promontory_ of the _Bosporus_; for they hang over the Sea in such a manner, that whether you sail to _Constantinople_ out of the _Black Sea_, or the _Propontis_, you may see them at a great Distance, prominent over the Chaps of the _Bosporus_. The third Valley seems to separate the other three Hills, which lie farther into the Continent from these. The Reason why I place six Hills in the _Promontory_ of the _Bosporus_ is, because these latter Hills all stand in a Row near the Bay, and are join’d together both at the Top and the Sides of them. The Plain which unfolds itself on the Ridge of the third Hill, descends gently into a Plain which hangs over the third Valley, and is six hundred and twenty Paces in Length, and as many in Breadth. CHAP. XII. _Of the third Valley._ The third Valley, which lies between the third and the fourth Hill, seems to be a double Valley; for in the Middle of it, it rises high, which makes it doubtful whether it be a part of the Valley, or the _Promontory_. That the Height of it is a part of the Valley, seems plain from the Height of the Arches, which reach from one Side of the Valley to the other; and it may be look’d upon to be the Ridge of the _Promontory_, from the Descent of the extreme Parts of it falling to the right and left, on each Side of the _Promontory_. On the right Side of which, it descends into a very low Plain, which, at its first Entrance, is three hundred Paces broad, and continues on upon a Level to the Length of five hundred Paces more; and though it sinks at Bottom into an equal Depth, yet the Pitches or Sides of it, in some Places, are higher than in others. For where the Plain is most hollow, there one of the Sides of it is three times higher than the other. From this Plain you ascend by easy Steps to the Top of the Middle of the Valley, which is six hundred Paces wide, except that small part of it in the Middle, where it is not above four hundred Paces in Breadth. Through the Top of this Valley, or _Promontory_, run the Arches of an _Aqueduct_ from the fourth to the third Hill, of the same Height, at the Top of them, with the Hills themselves. The Altitude of these Arches discovers how great the Descent is from them. For though they are alike equal in Height at the Top of them, yet this Height is very different, according to the Difference of their Situations. For they are very high at the Top of the Valley, which is a plain level Ground, but upon the Descent of the Hills not near so high, and continue to the