432 FOURTH REPORT — 1834. 



ever may have been the opinions of philosophers on this subject, 

 the fact was not known until Manfredi established it. Sabbadini 

 had given his opinion in his discourse on the Lagunes of Venice. 



Moutanari, in his essay entitled // Mare Adriatico e sua Cor- 

 rente esaininata, maintained that the rise of the bottom of the 

 Adriatic Sea was owing, not to the alluvion of the Po, as has 

 been asserted, but to the sands of the shores of the Mediter- 

 ranean brought by the current which runs from the Straits of 

 Gibraltar along the African coast, and through the Ionian Seas 

 into the Adriatic : his conclusions, however, are too fortuitous to 

 be quoted. 



The observations of Manfredi on the levels of floors of several 

 ancient buildings at Ravenna, such as the Cathedral, Rotunda 

 and Church of St. Vital, as compai-ed with the levels of the 

 neighbouring sea, and which Zendrini afterwards confirmed by 

 other observations of the same nature, are curious. Zendrini 

 observed that the rings formerly used to fasten boats to the 

 quays at St. Mark's Place, are now below the level of the sea j 

 that the subterranean church of St. Mark is no longer serviceable, 

 because it is below water ; that the ground plot of the Piazza is 

 sometimes overflowed in moderately high tides, although it liad 

 been raised a foot ; that in the island of Capri the whole plat- 

 form of an ancient Roman edifice placed on the sea-shore was 

 inundated; and he states that similar observations of Donati 

 along the coasts of Dalmatia gave the same results. 



The observations of Zendrini on the embouchures of rivers in 

 the Mediterranean apply with equal correctness to all rivers 

 which empty themselves into inland seas and lakes. 



Grandi repeated the experiments of Zendrini ; but although in 

 his treatise on the motion of running water he professes to fol- 

 low the principles of Galileo and Torricelli, his observations on 

 rivers indicate that he possessed very little knowledge on that 

 subject; his dissertations on the river Era and other rivers have 

 merely a local interest, without adding anything to the science. 

 The same may be said of the treatises of Cassini and Michelini, 

 although the latter was the first to show the art of regulating 

 rivers. 



But the treatises of Guglielmini on the measure of running 

 waters and on rivers are the greatest works of the Italian school 

 of hydrometry. The publication of these works originated with 

 the commissioners appointed in the year 1693 by Pope Innocent 

 XII. to investigate the state of the provinces of Bologna, Ferrara, 



a peninsula; Monemvasia, an island formerly the promontory of Minerva; the 

 Cothon of Carthage, now a swamp separated by the port of Lecheum; Corinth, 

 the port of Patara, and the Catacombs of Alexandria. 



i 



