398 ADDITIONAL NOTICES. [June 27, 1859. 



author undertakes to examine the doctrine of Montanari, and thus passes on 

 to the second part of his work. 



According to Mr. Cialdi, Montanari 's doctrine considered per se is far from 

 solid, and a small number of facts adduced would suffice to prove it erroneous. 

 But that doctrine being supported by the most celebrated men who have 

 treated the subject of the motion of waters, he feels the necessity of extreme 

 circumspection in his deductions while unhesitatingly refuting the same. 

 He therefore endeavours to enter gradually into the development of the 

 question in hand, with the paragraphs from 25 to 35, and as he proceeds he 

 gathers in new facts against the defenders of the said doctrine ; so that at the 

 37th paragraph he seems to think that he has annihilated it by weight of the 

 facts and by dictates of reason, and he sees rising on its ruins the new law of 

 sand-shift ings, the principles of which were already indicated by Castelli, 

 Boscowich, and De Fazio, but remained neglected on account of the prevailing 

 theory of Montanari. This new law of sand-shifting is held by the author as 

 an axiom. 



The author was under this conviction when he became acquainted with the 

 excellent * Considerations on the Protrusion of Shores and on the Sand Ac- 

 cumulations in the Ports of the Adriatic, applied to the Establishment of a 

 Port in the Pelusian Bay,' by the celebrated Paleocapa. 



It is easy to perceive that, those ' Considerations ' contradicting the two 

 principal propositions which form the basis of almost the whole edifice raised 

 by Captain Cialdi, he saw himself placed under the necessity either of re- 

 nouncing the authority of all the facts adduced in his work, or of making an 

 appendix to the same, which, based on the same facts and on others omitted 

 for brevity's sake, should prove the exactness of his arguments. After mature 

 reflection he adopted the second alternative ; and we gather from the Ap- 

 pendix he has published that a more thorough examination of the question 

 has given, according to his opinion, still greater evidence to all that he had 

 previously enunciated. 



In this Appendix he besides avails himself of the opportunity of adverting 

 to the intended Pelusian port ; he applies there his theory, and suggests a few 

 modifications in the piers which are to form that harbour. 



