While Phœbus down the vertic circle glides;
Now seen on ocean’s utmost verge to swim,
He sweeps it vibrant with his nether limb.
Thus height, and polar distance are obtained,
Then latitude, and declination, gained;
In chiliads next th’ analogy is sought,
And on the sinical triangle wrought:
By this magnetic variance is explored,
Just angles known, and polar truth restored.
The natives, while the ship departs their land,