SUMMARY" OF RESULTS. 
15 
cruises in a part of tlie ocean which, after him, was penetrated by no navigator for four 
centuries . 1 
The high tides in the estuaries of Britain are said to have made a profound 
impression upon Pytheas, and to have first suggested to him a theory of the tides. 
However this may be, Pytheas undoubtedly gave the Greeks a true notion of the tides 
in attributing them, two thousand years before Newton, to the influence of the moon . 2 3 
To Aristotle, who was a. contemporary of Pytheas, we are indebted for many Aristotlk 
important additions to oceanography ; an elevated intelligence, like that of the Stagyrite, 
must necessarily have been attracted to the study of the ocean, in the capacity both 
of naturalist and of thinker. That the sea was the object of his meditations and 
researches, is indicated by a legend as to the manner of his death ; it is reported 
that, despairing of ever being able to find the interpretation of the movements of the 
waters of the Strait of Euripus, he threw himself into the whirlpool. The specu- 
lative philosopher often appears beneath his observations, and his works abound in 
judicious views concerning the phenomena of the sea, bearing at once the stamp of 
remarkable sagacity and of an earnest and investigating mind. His doctrines relating to 
the ocean had so much influence that his ideas upon the subject were reproduced among 
the Romans and down to the close of the Middle Ages. 
Aristotle’s observations are scattered through his works on Natural History and His General 
P hysics, and the second book of his Meteorology commences with what may be called a CosIioorapiiy 
treatise on oceanography. He there deals, in particular, with the relations of land and 
sea. He regards the earth as a sphere, placed in the centre of the universe, round which 
other celestial bodies revolve. He establishes its spherical form by the fact that all 
things gravitate towards the centre, and by reference to the shadow of the earth during 
eclipses . 4 He regards the habitable world as being confined to the temperate zone ; all 
beyond the tropic to the south is uninhabitable from heat, while the land below the 
Great Bear is uninhabitable from cold. He adds that there must be in the southern 
hemisphere a temperate zone corresponding to the northern one, but does not say that it 
is inhabited. He ridicules the idea that the inhabited world is circular — a notion which 
appears to have been prevalent in his day as well as in the time of Herodotus. 
Humboldt believes that the following passage must have had much influence in 
leading up to the discoveries of Columbus : — “ It appears,” says Aristotle, “those are not 
1 St. Martin, op. cit., pp. 101-109 ; Bunbury, Ency. Brit., art. “ Pytheas.” 
2 Plutarch, Plac. Phil., iii. 17. Tiinaeus, who died about 265 B.c., and who contributed much to the extension f 
geographical knowledge of the western parts of Europe, was far from giving such an interpretation. He stated th.V 
the flux and reflux of the ocean were due to the rising of the great rivers which discharged themselves irom the 
mountains of Gaul. Their risings caused the water of the sea to retire, and when the rivers were no more swollen 
the reflux occurred (Tinueus, Frag., 36 ; Plutarch, Plac. Phil.). 
3 384 to 322 B.c. 
4 In these cosmic views Aristotle followed those of the astronomer, Eudoxus oi Cnidus, who lived a generation, 
before him. 
