IDO
HISTORY OF ENGINEERING.
Book I.
government produced many private and independent interests, which eventually caused thispeople to be subdued by the Romans. There is not a vestige or tradition of* any hydraulicworks executed by them, though there are considerable remains both of their sculpture andarchitecture.
The first work recorded is the Appian Way , undertaken in the four hundred and forty-second year from the foundation of Rome , and finished in five years by Appius Claudius ,called Coccus; during his censorship, which was prolonged beyond the legal term, he alsoconstructed the first aqueduct.
To form this road, it must have been necessary to drain the marshes to some extent, butof this we are not informed. A hundred and forty years afterwards, the Consul CorneliusCethegus undertook to do this more effectually; but various causes interrupted theprogress of these works until the time of the perpetual dictatorship of Julius Ca?sar, whointended to have performed vast projects, which were prevented by his death. Augustus ,who undertook to turn the course of the Tiber from Ostia , commenced his works on a moreextended plan, and it is supposed that during his reign, the canal on each side of the Appian Way was formed, which served for the purposes of navigation as well as drainage. Thisemperor also cut another large canal along the western side, between the Lakes Monaci,Caprolace, and Paola, passing the foot of Monte Circeo, and afterwards continued it towardsTerracina. Besides this canal, parallel to the shore, there arc on the other side two exca-vations, evidently made for drainage only, one of which is the Gorgo Leccino, intendedto conduct the water from the upper part of the marsh out of their basin towards FosseVerde; the other is the Rio Martino, whose line of direction is more in the centre of themarshes; this was the greatest work ever undertaken, but history does not mention whenit was executed, or who was its engineer. Nerva and Trajan improved the Appian Way ,constructed many bridges, and several inscriptions show the interest the latter emperortook in forming the road, but it does not appear that the drainage occupied any portion ofhis attention. There is very little mention of these marshes until the time of Theodoric ,who confided their drainage to the Patrician Decius, and several inscriptions found atTerracina mention works he performed at the end of the sixth and commencement of thefollowing century.
From the thirteenth to the middle of the eighteenth century, the draining of the Pontinemarshes was a subject that occupied the attention of the successively appointed popes.
Leo X. and Sixtus V. expended vast sums, and the first gave to Julius de Medici, notonly authority, but money to pursue the work ; it is to him that we may attribute thecutting of the canal, Portatorre di Badino, the works being conducted under an engineerof the name of Jean Scotti: Fiume Sisto was a canal executed under the latter pope, thecourse of which nearly follows that of the ancient Fiume Antiquo; this excavation wasperformed about the year 1588, under the direction of the civil engineer, Ascanio Fenizi.
In the year 1759, Clement XIII . turned his attention to this important matter, andordered a detailed account to be drawn up of the state of the Pontine marshes, and anestimate to be made of the expense that would be necessary to complete one portion of thework ; but a famine happening in the year 1665, when the inhabitants of the papal stateswere much reduced, the funds collected were exhausted for food, and consequently nothingwas done in the way of draining. Clement XIV . Ganganelli , who was his successor , didnothing; and it was not until Pius VII. , in the year 1775, was elected pope, that theworks were recommenced; he altered, during his sovereignty, the character of thesemarshes, and performed several very important' excavations for the purpose of completingthe drainage.
These marshes contain an area of 1,106,370,000 square metres, though by some it isestimated at 1,302,610,700 square metres; and it is calculated that the average quantity ofrain that falls into this vast basin amounts to 930,064,0-42 cubic inches. The volume ofwater that is discharged, however, is more than double that quantity, being estimated at2,352,573,939 cubic metres.
In the calculation from whence the above is taken, the greatest discrepancy seems toarise in the allowance made for evaporation and infiltration ; the water which pours intothem, and so adds to the quantity beyond that produced by the rains, is brought down bythe rivers Ninfa, Cavata, Fiume coperta Cavatella, and L’ffente.
The canal Pio, which discharges a considerable quantity, has a very regular fallthroughout; for its first length it is only '00072 metres in a metre, and afterwards•000068 metres in a metre for the remainder of its course. The fall of these waters in alength of 3728 metres being 0*734 metres high water, and *525 when at its lowest.
Various methods are adopted to keep open these canals, and for several centuries it wasthe practice to drive herds of buffaloes through them, which either trod down, or destroyedthe aquatic plants which are here produced in abundance. A cylinder about 18 inches indiameter, and 10 feet in length, was afterwards used ; this roller, armed with scythes,by means of a chain was moved along by a punt or boat; twelve buffaloes were attachedto drag it when required for use ; another method was to mow down the weeds and plants