THE LESSON OF EVOLUTION 7 



sailed round the world, and demolished the old dogma 

 that the earth was a flat disc, with Jerusalem in its 

 centre. Then the invention of the printing-press 

 spread the news far and wide, and from that time 

 forwards science took an important position in the 

 world. 



Long before this, however, the idea of law and order 

 in Nature had been gradually growing. The wonders 

 of the thunderstorm, of eclipses, even of the rainbow, 

 had been explained as the result of physical laws ; and 

 the consequence was that the belief in the crude 

 polytheism of the ancients had been destroyed. 



The advance of scientific knowledge was at first 

 very slow, until, in the seventeenth century, the great 

 improvements which were made in mathematical 

 analysis, as well as the invention of the telescope, 

 enlarged men's ideas enormously, and added vastly to 

 their powers of observation and reasoning. Before 

 the century was over the size of the earth had been 

 ascertained with tolerable accuracy, and the law of 

 universal gravitation had been discovered. In the 

 eighteenth century great progress was made in the 

 experimental sciences of physics and chemistry. 

 Electricity was detected, as also was oxygen, and 

 this laid the foundation of modern chemistry. In- 

 struments of precision for weighing and measuring 

 were invented ; and, at the end of the century, the 

 distance of the sun was approximately ascertained ; 

 and it was proved that matter was not destroyed 

 when it was burnt, but only rendered invisible. The 

 discovery that matter was indestructible led, in the 

 nineteenth century, to the further discovery that the 

 physical forces are so correlated that one can be 



