[712] 
metrica de DIMENSIONE FIGVT{JTijjM , Authore 
Divide Grcgorio, in Ac ademz a Edinburgenfl Mathefe^ 
OS Profeffore. Edinburgi in 4«. 1^84. II. L Art de 
Tailler les Arbres Fruitiers ; ^ un. Trait de Lufage des 
Vmits des Kthtts, aVsLviiin 12. 1(^83. 
A further account of the Bridg Pont St- Efprit, 
whereof before^ Numb. 1 60. together witk a paral- 
lel Hiftory of fome other Bridges at Rome : In a 
Letter from the ingenious Mr. Tankred Robinfon 
/a Pr. Martin Lifter. 
Ince my laft concerning the Bridge at Vont St. Ef- 
prit^ I have found fomething more in that kind for 
your further diverfion ; I doe not doubt but you 
ftill retain a frefh Idea of the ftately ruins ofthe Mo^^r;^ 
Bridge 2it Avignon^ which^hath yielded in many places 
to the extreme rapidity, and violence of the J^ofne, 
Its fall in my opinion may be afcrib d to three defeds:,- 
firft, it was not fo Multangular, as that at St. Efprit : Se- 
condly, it wanted in ^ or 4 places, the little Arches divid- 
ing the feet of the great oxies, and in thole parts it hath 
fulFer d moft for where thofe ufeful fluces are, there I 
obferv'd the bridge to ftand ftill the mo>ft entire. Third- 
ly, the Pedejials (or as you very properly call them, //<?r/- 
^o?7tal Arches) were not fo Geometricaily and exactly 
laid, as thofe of Pont St. Ejpr it, th^ix jettings out were few, 
and they not gradually contra£led, fo that the force of 
the ftream muft be the greater upon the Fabrick. 
Now that we are upon this fort of Hijiory^ I will ven- 
ture to carry you from the 7?/^^^ to the73'^^rj which, 
though not fo Iwift as the T{hefne, yet is fubjed: to greater 
inundations; as many infcriptions aifure us. No J{iver 
