f^04} M. Van Swinden 07i the Invention of Pendulum-Clocks 
pendulum-clocks were constructed in England ; still the num- 
ber of them must have been small : for Derham, an English- 
man, who published a work on watchmaking in 1700, says, 
that after Huygens had invented pendulum-clocks, and made 
many of them, a Dutch watchmaker of the name of Fromentil 
came over from Holland about the year 1662, and constructed 
the first ever seen in England. He adds, that there was still one 
extant in Gresham College, which Bishop Seth of Salisbury 
had made a present of to the London Society. This, however, 
I am disposed to think relates only to pendulums with cycloidal 
cheeks, Huygens himself mentions, in a journal of his voyage 
to England in 1661, that Mr Goddart had, on the 6th of April 
of that year, at a meeting of the Society at Gresham College, 
shewn him in his apartments three fine pendulum-clocks. 
Some watchmakers in Holland, who, notwithstanding the pri- 
vilege of the States granted to Huygens, imitated his pieces, con- 
cealed as much as possible the new device, and went even so far 
as entirely to dispute his claim to the discovery. He complains 
of this abuse in the dedication to the States of Holland, prefixed 
to the Horologium ; and was even compelled to prove his claims 
in a lawsuit, which he directed his workman Coster to institute 
against a watchmaker at Rotterdam. 
This, which took place in Holland under Huygens^’s eye, was 
much more to be expected in foreign parts, and actually hap- 
pened at Rome, where the description published by Huygens 
had been sent at the end of 1658. Jilgidius Gottignies, a pro- 
fessor at the latter place, wrote in August 1659 to Gregorius k 
Sancto Vincentio at Ghent: ‘‘ One of these days, a watchmaker 
to the Pope constructed a clock similar to that of which Huy- 
gens sent you the description. He was highly elated with this 
new and admirable invention, which he said was his own,J and 
had asked all mathematicians to come and see it. All were 
loud in their praises. For as he had prudently concealed the 
chief contrivance, so that the spectators saw nothing but the 
hands and pendulum, they were astonished, and could not suffi- 
ciently testify their admiration of a thing of which they had 
heard nothing, and bestowed the greatest applause on the pre- 
tended discoverer, when I, who had been admitted among 
them by Father Athanasius Kircher, suddenly checked these 
