276 Address of Sir William Thompson. 
discovery was made. It was by a long train of mathematical 
calculation, founded on results accumulated through prodigious 
toil of practical astronomers, that Newton first demonstrated the 
the Earth. Then first, we may suppose, came to him the idea 
of the universality of gravitation; but when he attempted to 
present at a meeting of the Royal Bacistys he heard Ra 
i icard, whic 
Earth's radius. This was what N ewton required. He went 
a friend: then (and not when, sitting in a garden, he saw aa 
apple fall) did he ascertain that gravitation keeps the Moon 
ber orbit. : 
_ Faraday’s discovery of specific inductive capacity, which 
maugurated the new philosophy tending to discard action at a 
distance, was the result of minute and accurate measurement of 
electric forces. : 
Joule’s discovery of thermo-dynamic law through the regions 
Andrew’s discovery of the continuity between the gaseous 
and liquid states was worked out by many years of laborious 
and minute measurement of phenomena scarcely sensible to the 
naked eye. 
element. He showed the relation beween electrostatic and ele 
_ Womagnetic units for absolute measurement, and made the 
