Book IV chapter 19

The variation in the interior of large Continents.

M ost of the great seas have great variations; in some parts, however, they have none, but the true directions are toward the pole. On continents, also, the magnetick needle often deviates² from the meridian³, as on the edge of the land and near the borders; but it is generally accustomed to deviate¹ by a somewhat small arc. In the middle, however, of great regions there are no variations. Hence in the middle lands of Upper Europe, in the interior of Asia, and in the heart of Africa, of Peru, and in the regions of North or Mexican America, the versorium rests in the meridian.

1 deviate   

v.(from)背离，偏离

参考例句：

• Don't deviate from major issues.不要偏离主要问题。
• I will never deviate from what I believe to be right.我绝不背离我自信正确的道路。

2 deviates   

v.偏离，越轨( deviate的第三人称单数 )

参考例句：

• The boy's behavior deviates from the usual pattern. 这个男孩子的举止与一般人不同。 来自《简明英汉词典》
• The limit occurs when the ordinate deviates appreciably from unity. 这个限度发生在纵坐标明显地从单位1偏离的时候。 来自辞典例句

3 meridian   

adj.子午线的；全盛期的

参考例句：

• All places on the same meridian have the same longitude.在同一子午线上的地方都有相同的经度。
• He is now at the meridian of his intellectual power.他现在正值智力全盛期。