126 THE WORLD MACHINE 



modern mind which most resembled the Syracusan's. Archi- 

 medes did not make the measures of acceleration ; Galileo did, 

 but as little to Galileo as to Archimedes did the light come. 



It is to be noted, apropos of the failure of Archimedes, that 

 they seemed to lack in that day a minute and accurate measure 

 of time. They had hour-glasses, and the clepsydra, a water- 

 clock. They understood well how to "weigh" time that is, 

 to measure in the balance the amount of water or mercury 

 escaping in the interval covering any given action to be observed ; 

 but while it has been used with more success in our modern 

 day, it was a clumsy method. It is evident that it was Galileo's 

 discovery of the pendulum and his application of it as a pulse- 

 counter, which opened the way for his measure of the rate 

 of acceleration yet another among ten thousand instances of 

 the dependence of progress and discovery upon machines, that 

 is to say, mechanical devices supplementing the crude human 

 implements of hands and eyes. 



It is curious to reflect what might have been the effect had 

 the measure of acceleration been made. They had a highly 

 developed geometry, an astronomy as well. They knew the 

 distance of the moon, and its size, almost as well as Newton ; 

 they knew its orbit, and could calculate the distance it falls 

 toward the earth, each moment of its flight, almost as well 

 as he? Galileo's Discourses and Mathematical Demonstrations 

 concerning Two New Sciences, dictated by a blind old man 

 under confinement at the hands of the Roman Inquisition, 

 appeared in 1638 ; therein these measures were first related. 

 Newton's " Mathematical Principles of Natural Philosophy," 

 the Principia, in which the law of gravitation was announced, 

 was given to the world in 1687. Just half a century lay 

 between. 



When Xerxes crossed the Hellespont, says Diogenes, Anaxa- 

 goras was twenty ; he was born, then, about the year 500 B.C. 

 The sack of Syracuse and the butchery of Archimedes came 

 nearly three centuries after. Three centuries later still the 

 University of Alexandria and its great line of physical investi- 

 gators still flourished ; Ptolemy, the astronomer, was writing 

 his Syntaxis the Almagest, and his treatise on the refraction 

 of light. 



Six hundred years ! Time moved slowly then. Though in 

 the reign of Neku L, 600 B.C., Phoenician mariners might achieve 



