178 THE INTELLECTUAL RISE IN ELECTRICITY. 



heavens, and not the poles only, influence the magnet ; 

 but he is very cautious, and throws the burden of success 

 or failure upon the maker. Make a globular magnet, he 

 says, and find the poles. Then affix two pivots, on which 

 the globe may turn. See that it is equally balanced and 

 turns easily on the pivots, and try this repeatedly for many 

 days and at different times in the day. Now place the 

 stone with its axis in the meridian of the place, and dis- 

 pose its poles so as to correspond to the elevation or de- 

 pression of the heavenly poles in the region where you 

 may be. And then 



But Peregrinus here drops his affirmative style and takes 

 refuge in u ifs." 



^If the stone is moved according to the motion of 

 the heavens, you will delight in having found so wonder- 

 ful a secret; but if not, impute the failure rather to your 

 own unskillfulness than to nature." 



What he believed would happen he had never tried 

 the experiment was that the globular magnet, being on 

 the (then considered) motionless earth, and being in- 

 fluenced by the heavenly vault revolving about it, would 

 follow the motion of the sky and so rotate. 1 He thought 

 it might even serve as a timepiece. But this delusion 

 nevertheless bears good fruit for, he adds, "in this posi- 

 tion (i. e., in the magnetic meridian) I believe the virtues 

 of the stone to be best preserved," which is true. 



In order to appreciate the remarkable improvements 

 which were embodied in the instruments which Peregrinus 

 now proceeds to describe, it may be recalled that the ex- 

 isting compass was nothing but a needle supported on a 

 reed so as to float in a vessel of water. It simply showed, 



1 " It was the opinion of Pet. Peregrinus, and there is an example pre- 

 tended for it in Beltinus (Apiar. g. Progym., 5, pro., u) that a mag- 

 netical globe or terella being rightly placed upon its poles, would of 

 itself have a constant rotation like the diurnal motion of the earth ; but 

 this is commonly exploded, as being against all experience." Wilkins: 

 Mathematical Magick, London, 1707, 5th ed., Chap. XIII. 



