58 PROGRESS OF SCIENCE. 



determined that comets are beyond the moon, and cut the 

 firmament in all directions; made numerous beautiful physical 

 and astronomical instruments. He earnestly advocated 

 experiments, and took nothing for granted without rigid 

 verification.* He was the reformer of the astronomical 

 science beyond all question. 



15481620. Stevinus elucidated some of the LAWS OF 

 PRESSURE, motion, THE LEVER, and the equilibrium of 

 liquids. 



Ab. 1546. Lelio reformed the CALENDAR in 1581 a 

 proof that " observations " were pursued everywhere. 



1550 1617. Napier developed and perfected LOGA- 

 RITHMS there were several reprints of his works in a 

 few years. This new mode of calculation was a discovery 

 which has multiplied perhaps " hundredfold the working 

 process of every computer, and has rendered easy calculations 

 which were before impracticable." 



1550 1600. Bruno (Giordano) lectured on and popu- 

 larised the COPERNICAN SYSTEM ; asserted that other worlds 

 might be inhabited besides ours, entertaining the opinion, as 

 early as 1591, that the stars may be suns attended by planets 

 like our earth. He attempted to establish the mechanical 

 conception of the universe (Democritus's view) . He denounced 

 Aristotle and authority as early as 1580 (in Oxford in 1583). 

 For his fourfold offence he was burnt alive in 1600. He must 

 be remembered as one of the great martyrs of science. 



1560 1621. Harriot explained the origin of colours in the 

 RAINBOW, more fully than Roger Bacon and Vitellio had done, 



1564 1642. Galileo, the greatest man of science, together 

 with Archimedes, Hipparchus, and Alhazen, the world pro- 

 duced before Newton, invented the THERMOMETER, one 

 of the most important agents in our possession, in I597 

 and from that time the phenomena of heat could be studied,, 

 and these of course include a vast number of chemical 

 phenomena. He improved Lippershey's or Janssen's 

 TELESCOPE and microscope the starting point of modern 

 astronomy and physiology, and with the assistance of the 

 telescope made great discoveries. He created DYNAMICS- 

 * See Appendix V. 



