331 
of the Magnetic Poles qfilie 'Earth. 
tion of the compass, more than any other discovery, iias given 
us possession of the whole circle of the earth. Without its 
guidance, navigation must have been confined to sailing along 
the sea-coast, without losing sight of land. By aid of the com- 
pass, the seaman can always steer his ship in a certain direction, 
ascertaining what angle her course makes with the meridian. By 
means of the log he measures how many miles he has sailed. 
From his course thus and his distance, he has simple geometri- 
cal principles by which he can calculate how far he has advanced 
south or north, east or west. He thus always knows, too, where 
he is. To steer by the stars was a thing very difiicult, since the 
heavens were always revolving : when they were covered with 
clouds, it was altogether impossible. It was the compass which 
shewed to Columbus a path over the Atlantic Sea to America, 
which guided Vasco de Gama round the Cape of Good Hope, and 
the undaunted Hernando Magellan round the globe. In the 
tract of these heroes followed enterprising seamen, who, from the 
hope of gain, were continually endeavouring to extend their dis- 
coveries in all directions, till the whole surface of the earth now 
lies open to us, from the ice-bound coasts of North America to 
the southern Thule. In the South Sea, at Otaheite and the 
Sandwich Isles, arise Christian states, where, with Christianity, 
the mind is awakened to a more intellectual animation. In 
the tract of commerce slowly follows the higher cultivation of 
Europe, which shall at last encircle the whole earth ; so that 
different races, endued with different talents, shall in the end 
unite in rearing the temple of wisdom, which now stands before 
our sight as an ideal vision. But what reaction has this disco- 
very occasioned in our own part of the world ? The gold of 
America has flowed in streams to Europe. States have risen 
and sunk as the tide of commerce was in their favour or against 
them. Envy and emulation awakened men’s passions, and ex- 
cited the most bloody wars and revolutions. New wants were 
introduced, and with them new activities. The sciences them-- 
selves felt a mighty excitement to progress. Long dangerous 
voyages made it necessary to discover more certain methods of 
determining a ship’s place at sea, than were formerly known ; 
for the log is attended with certain unavoidable mistakes, which, 
during a voyage of several months, rise to a considerable amount. 
