4^ M. Van Swinden on the Invention (^Pendulum-Cloaks 
Figure de VHorloge a Pendule qui est a Florence dans le vieil 
Palais de Medicis^ to which Huygens added with his own hand 
as on the former : Missum a Ser°. Pr. Leopoldo ad Ism. Bulli- 
aldum.^ Ao. 1660,* cum descriptio Horologii mei edita Juisset^ 
Ao. 1 658. This representation of a public clock on the old Palace 
of the Medicis, which is of itself sufficiently interesting, when 
conjoined with the same gentleman’s correspondence, bears im- 
mediately on the subject under consideration. In the begin- 
ning of 1659, he promises to send a description of the clock 
which was then either undertaken or undergoing repairs by or- 
der of the Grand Duke, ( auquel M. le Grand Due fait tra- 
vailler ). The following year, when the description was sent, 
we find allusion to it made in several letters ; the words are 
nearly decisive ; in one, the clock which the Grand Duke had 
got up ^ (fait accommoder); in another, which he had had adjust- 
ed.^ (fait adjuster ^ ; in a third, which he had had repaired with 
the pendulum.^ ( raccommoder avec le pendule.^ Leyden MS.) 
The representation itself, Plate I. Fig. 6. (which I have sometimes 
suspected to be one of Vincenzio Galileo’s old designs perhaps 
somewhat altered), shows an escapement with a single pallet, as 
appears in the separate figure of it below, and where it is seen 
in front. The pendulum appears to be very light, and to de- 
scribe very great arches. It looks like an imperfect contrivance, 
and I am in doubts whether it could answer the purpose. The 
remainder relates to the motion of the hands and the striking. 
I shall add as a surprising fact, that Viviani, who wrote the 
life of Galileo, and set a high value on his reputation, speaks of 
him only as the inventor of the pendulum, a thing never called 
in question, but nowhere of the pendulum clock ; and this will 
appear the more surprising, when it is recollected, that Viviani 
has been cited among the authorities to prove Galileo’s claims to 
the invention. It is true, Tiraboschi, p. 155. afterwards pro- 
duced a letter said to be written by him in 1678, in which he 
speaks of this latter claim as a just pretension, (justa preten- 
sione ) ; but, on the other hand, we know that Viviani lived un- 
der the same roof with Galileo the three last years of his life ; 
that he worked with him ; that the correspondence with the 
States-General was going on during that time ; that he knew of 
it, and has actually mentioned it (F?ia, p. 78.) ; but without a 
