io SCIENCE OF THE GREEKS. PT. i. 



understand that as the sun is low down in the morning, and 

 gradually passes overhead during the day, it will cause the 

 pin to throw its shadow in different directions at different 

 hours. 



In this way Anaximander taught the Greeks to measure 

 the time of day. He is also said to have been the first as- 

 tronomer who understood why we see the bright face of the 

 moon growing from a crescent to a full moon and then di- 

 minishing again. To know this he must also have known 

 that the moon moves round the earth every month. You 

 can imitate the changes of the moon if you take a round 

 stone and hold it just above your head between you and 

 the sun ; you will then have its shady side towards you ; 

 pass it slowly round your head, you will find that you see 

 first a bright edge appearing, then more and more of the 

 bright side, till when the stone is on one side of your head 

 and the sun the other, you will see the whole of one side 

 of the stone reflecting the sun's light this is a full moon. 

 Pass it on slowly round, and you will see this bright side 

 disappear gradually till you bring it back to its old position 

 between you and the sun, when it will be again dark. This 

 is what the moon does every month, producing what are 

 called the phases of the moon. Anaximander also made a 

 map of the world, or at least of as much of it as was known 

 in his time. 



J Pythagoras, one of the most celebrated of the learned 

 men of Greece, is the next who told us anything about 

 science. The time and place of his birth are uncertain, 

 but he lived between 566 and 470 B.C. He travelled in 

 Egypt, and learnt much there, and afterwards settled at 

 Tarentum, in Italy, where he founded the famous sect of 

 the Pythagoreans. You will read of the opinions of Pytha- 

 goras in books of philosophy, but we are only concerned 

 with wiiul he taught about nature. 



