184 SEVENTEENTH CENTURY. PT. ill. 



of the seventeenth century. It began, you see, with certain 

 simple facts ; by Galileo seeing that bodies existed in the 

 heavens which were not known to be there before ; it ended 

 in the beautiful law of which we have just spoken. But I 

 want you particularly to notice that this end would never 

 have been reached by men who were content to sit down 

 idly and talk of the greatness of God. It was the result of 

 real work by men who tried first to learn the facts, and from 

 these to prove reverently the way in which it pleases God to 

 bring them about ; and in this labour of love, being brought 

 face to face with the infinite grandeur of nature, they learnt 

 that true humility which led Newton, the greatest of them 

 all, to feel that he was but as a little child gathering pebbles 

 on the shore of the great ocean of truth. 



Physics. If we now turn to Physics, we shall find that 

 the way to knowledge lay still along the same road of patient 

 inquiry. Torricelli's barometer and Guericke's hemispheres 

 of Magdeburg both proved by direct experiment that the 

 atmosphere round our earth is pressing in all directions 

 equally with great force ; and this again brings us round to 

 the force of gravity, which is the cause of this pressure ; 

 while Boyle's experiment showed that air is elastic, being 

 compressed in exact proportion as the weight upon it is 

 increased, and expanding again directly it is diminished. 

 Newton showed that this elasticity of air gives rise to the 

 waves of condensation and rarefaction, which convey an 

 original impulse across wide spaces and produce the effect 

 of sound upon our ears. 



Again, in the subject of Light, we begin with hard dry 

 facts, which doubtless you may have thought it wearisome to 

 master, but we end with a theory so wonderful and beautiful 

 that it seems more like a fairy-tale than sober science. The 

 first step here was the invention of the telescope, which, 



