46 M. Van Swinden on the Invention of Pendulum-Clocks 
labours of his soil Vincenzio Galilei were such as newer to have 
led to a decisive- or satisfactory result, that they were scarcely 
known^ and never^came to the knowledge , of Huygens : That 
the attempts (of others, seem likewise to have failed of complete 
success, so that even Hevelius, who ; approached nearest jto, it, 
acknowledges in his Machina that, before obtaining it, 
he. was anticipated by another That it was Huygens who first 
of all, in December 1656, found out the perfect way of connect- 
ing the motion of the pendulum with that of a clock : That he 
made known- the discovery to. his numerous correspondents in 
.1657, published the description, and sent specimens of it every- 
where in 1658, and afterwards laboured incessantly to improve 
upon the adaptation of his iprinciples : That the invention was 
no sooner known than it was adopted, and balances in. a short 
time removed from all clocks to make room for the pendulum, 
from which it lias happened that many clocks were afterwards 
found having a pendulum, which nevertheless, by the date, ap- 
peared to be of a much earlier construction. 
I shall conclude by taking notice of an opinion of the lateice- 
lebrated Ferdinand Berthoud, expressed in his Histoire de la 
Mesure du temps, p. 101., that Huygens has indeed all the me- 
rit we ascribe to him ; but; that this does not amount to an hi- 
vention, and he refuses him the rank of about a con- 
trivance which he contends is nothing but a mQVQ substitution oi 
the pendulum to the balance, the mode of acting by means of 
pallets being perfectly the same in both. This opimon,. which 
Mr Delambre has already been at some pains to refute, in the 
Memoirs of the Institute for 1808, appears scarcely fair, when 
it is considered that a great difference exists between balances 
which acted merely by their inertia, and the pendulum,, which 
is possessed of a principle of motion independent of the clock ; 
and it is farther considered, how admirably this independent mo- 
tion is combined with that of the clock, regulating instead of 
disturbing it, and being itself kept in motion by it, without, 
however, losing any part of its independent rate. Nor was the 
substitution, as originally made and proposed \ in the Horolo- 
gium, where the arbor with the pallets stands upright, so ob- 
vious or so easily effected, as it afterwards appeared in the im- 
proved form given in the Horologium Oscillatorium, wheve^ 
