CHARLES AUGUSTIN COULOMB 153 



work, it was suddenly brought nearer to being understood as a 

 unity, inasmuch as all phenomena could be referred to two elec- 

 tricities and two magnetisms, - themselves not less wonder- 

 ful, of course - acting according to the law of inverse squares. 



The first discovery of magnetic and electrical phenomena 

 is of very ancient origin. The lodestone, or magnetic iron 

 ore (no doubt so called from its place of first discovery, the 

 town of Magnesia in Lydia), with its property of attracting 

 small particles of iron, and the similar property of amber 

 (called by the Greeks Elektron) when rubbed, of attracting 

 small bodies, was known long before our era. Artificial 

 magnets of steel were also made by stroking with lodestone, 

 and it was known very early that magnets, suitably arranged 

 so as to be free to move, pointed in the direction of north 

 and south, a matter of great importance for navigation on 

 the open sea. The small deviation from the true meridian, 

 called the declination, had also been noticed. Columbus 

 noticed on his journey to the west that the easterly declina- 

 tion of the Mediterranean gradually reversed in direction 

 and became increasingly westerly, which caused him great 

 concern in view of his complete ignorance of the cause; for 

 when the sky was overcast he had no means of keeping on 

 his course except the compass. 



Only in the year 1600 was further progress made. Gilbert, 

 Queen Elizabeth's doctor, made extensive experiments with 

 artificial magnets; he was indeed the first person who in- 

 vestigated the phenomena scientifically. He found among 

 many other things, the fact that could only be fully appre- 

 ciated after Coulomb's work was known, namely that al- 

 though the magnetic forces proceed from the poles, of which 

 every magnet has two, and of which those pointing in the 

 same direction repel one another, it was never possible to 

 obtain a single pole separately. For if a lodestone or an 

 artificial magnet is broken into pieces, each piece again ex- 

 hibits two poles, which lie in the same directions as those 



