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Ferrara, who were desirous of conducting the Itheno to the southern extremity of theLake Comacehio, and carrying its waters to the sea through the Po di Priinaro.

Zendrini was invited, on the death of these celebrated engineers, to confute the opinionswhich they had given in their reports, and which the inhabitants of llologna wereinclined to adopt: on this occasion appeared his celebrated work, entitled “ Considerazionisopra la Scienza dellc Acque correnti, e sopra la Storia naturale del Po this was publishedin 1717. After this work appeared, the Duke of Modena appointed him his chiefengineer; and in the year 1720, by the decrees of Venice , he was nominated superin-tendent of the waters, rivers, canals, lagunes, and ports belonging to that city. Thisrepublic always appointed two of its most eminent philosophers to act as engineers, andmaintain the watercourses of the city in proper condition: 6ome of these were menfamous for their knowledge in hydraulics; among them was Christopher Sabbadino,nominated Prote in the year 1542.

Zendrini occupied himself during the superintendence of these important works atVenice with compiling an account of the ancient and modern state of the lagunes, whichwas published about sixty-four years after his death ; it is entitled “ Memorie storiche del’Stato, antico e moderno, delle Lagune di Venezia, &c.,” printed at Padua, in two quartovolumes.

This history comprises the period between 1300 and 1700; Zendrini cites a letter ofCassiodorus, which gives a tolerably exact account of the state of the lagunes and Venice between the fifth and sixth centuries, which is highly interesting ; and the numerous platesgiven arc curious with regard to levels, and the means adopted to execute the differentworks which were required to keep the canals open.

Zendrini was employed to survey the country round the port of Viareggio in the re-public of Lucca; his report was printed at the time. In it are many observationson the level of the sea; he commenced and executed works in this part of Italy , whichameliorated the condition and health of the inhabitants; the good effects of which weredestroyed by the intestine animosities that happened afterwards.

Clement XII . employed him in 1731, to report upon the state of the country aboutRavenna, which was occasionally inundated by the waters of the Roneo and IVIontone;these rivers he turned into new channels, and in 1741 published at Venice an account ofwhat he had performed.

Soon afterwards appeared his famous work, “ Dellc Acque correnti,” to which subse-quently was added the work entitled “ Relazione per la Diversionc de Fiumi Roneo eMontone.”

In the first of these the author gives general observations on the nature of fluids, treatsof their motion when issuing from reservoirs by simple orifices, as well as by pipes ; he thentakes up the subject of running water, the methods adopted to ascertain its velocity, and itseffects upon the beds and banks of rivers or canals: he also treats of the breaking down ofdykes and dams, the means by which these effects may be prevented, and the differentmethods usually adopted to divide a stream ; the draining of lands: a description is .addedof various improvements, that in his opinion might be made in some hydraulic machines.

This work shows distinctly the state of hydraulic knowledge at the time of its pub-lication; it rectifies many ancient theories, and is enriched with ideas new at the timethey were made known ; it was justly considered a chef-d'oeuvre by his contemporaries,and, notwithstanding the progress that has been made since on these subjects, it is a bookwhich every intelligent engineer should possess. Zendrini died in the year 1747, and theVenetian senate decreed him great honours.

Lazarettos in Italy _That at Genoa is near the sea, and comprises two spacious courts,

one of which is devoted to goods which are infected, and the other to those which may ormay not be so. In the middle of each of these courts is a chapel; three sides are sur-rounded by buildings three stories in height; the fourth contains the apartments of thephysicians and medical attendants. At the entrance is a guard-house ; three sides of thecourts are occupied by corridors, 10 feet 9 inches in width, separated by doors, sothat the crew and passengers of different vessels may be kept apart. From these corridorsthe rooms are entered, which are occupied by those in quarantine; they are 15feet 7 inches,by 14 feet 3 inches, and 11 feet 6 inches in height.

On the upper floors there are in front thirty-six rooms, besides twelve occupied by thegovernor ; on one side are ten, on the other eleven rooms, all of one size, viz. 16 feet 9, by14 feet 9, and 11 feet 6 inches in height; each has two windows opposite one another, sothat a thorough ventilation can be obtained ; they are placed at a height of 6 feet abovethe floor, and are 4 feet by 3 feet. The floors are paved with brick, and the rooms arevaulted ; they have a fireplace in one angle, and in another a small closet containing theurinal and drain. All these upper rooms open into a spacious corridor, 11 feet in width,the windows of which are towards the court ; and there arc also doors so contrived, thatthey can shut off three or four rooms as may be required.

The windows are barred with iron and have shutters, hut arc not glazed.

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