by Cliristimi Huygens, ,^E05 
plaudits, by mentioning the name of the author, and exposing 
the hidden artifice. Father Kircher has asked me to instruct a 
workman how to make such a clock, which I undertook to do.’’ 
{Leyden MSS.) 
But we come to more serious attacks on the rights of Huy- 
gens to be considered the inventor of pendulum-clocks. These 
arose more especially in Italy, where the invention has been as- 
cribed to Galileus Galilei, and his son Vincenzio Galilei. As 
this claim has been asserted in several works, even of the pre- 
sent day, and with some appearance of reason, it becomes ne- 
cessary to show, from original documents, how far Galileo and 
his son had gone, and to examine the real truth of the above- 
mentioned assertions. This is the chief purpose of this paper ; 
•and I flatter myself to be able to set the whole matter at rest 
for ever ; and, far from detracting any thing from the just 
claims of Galileo, to place these, on the contrary, in their proper 
light, by pointing out, in a much clearer manner than has ever 
yet been done, what Galileo actually accomplished. 
I shall first state the nature of the claims set up against Hu}"- 
gens, before entering upon a critical examination of them. 
They may be learned from the introduction to the Horolo„ 
glum Osclllatorlum^ published in 1673, where, in a firm, though 
moderate manner, he asserts his right to the honour of the 
discovery, Nunc cum haec omnibus nota sint, (namely, that 
he, Huygens, had fitted up clocks with a pendulum as early as 
1657, and sent specimens of them, along with a printed descrip- 
tion, every where the following year,) facile apparet quid de 
illis existimandum sit qui septem post annis eandem construc- 
tionem, quasi a se suisve amicis profectam libris suis vendita- 
runt.” It was probably after reading these words, that Prince 
Leopold de Medicis wrote in 1673, the letter quoted by Tira- 
boschi, from the Lettre hiedite dHomini and addressed to 
Huygens : Per quello che riguarde alV invenzione del pendoley 
con asserzione dettata da animo slncerissimo^ cosiantemente le 
affirmo di credere mosso da un forte verosimlle, che d notizla di 
V. s, non sia per alcun tempo venuto ll concetto^ che sovvenne 
ancora al nostro Galileo di adattare llpendolo alV orlolo ; poiche 
cld era e pochlsslmi noto, et Fistesso Galileo non avea rldotto aW 
attoo practlco cosa veruna di perfettoj a tel conto^ come si vedc 
