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At the Manhattan valley, he continues:'Here was an opportunity for constructing a work of architectural beauty and boldness, by building up with arcades of arches, one line above another, and thus maintain the regular inclination of the aqueduct; but considerations of economy forbad it. During the progress of the bridge, the water is for the present conducted over a low embankment, and advantage has here been taken of a difference of level of 120 through an aperture of seven inches to a height of 115 feet.'—p. 112.
Nature has scarcely in any instance subwith a more pleasing result than in the ascent mitted her agencies to the guidance of art of one of these stately columns, which we think in its simple beauty is usually a better is divided in ascent or broken in its fall by disposal of a powerful current than where it ornamental devices. We say this with due reverence for the two splendid fountains on the esplanade of St. Peter's, but also with a lively recollection of the jet d'eau of some eighty feet which adorns the royal gardens Yorkers so pleasing an object of pilgrimage We envy the New as Mr. Tower describes in the following passage:—
of Herren Hausen.
feeder-an open channel protected against | feet. For a distance of 18 feet at each end of the action of the current by masonry-an the pipes there is an inclination, and the remainder of the distance across, 1341 feet, they arched culvert or conduit composed essenare level.'-p. 110. tially of masonry and iron pipes.' The open channel was condemned as liable to filtration, waste of banks, evaporation, admission of impurities from varieties of soil, and as incapable of thorough repair without permanent stoppage of supply. Protection by masonry would obviate some of these objections, but others remained. If iron pipes could be laid at a regular inclination from the fountain reservoir to the city, the expense would still be greater than masonry. Should they fol-feet, to form a magnificent jet d'eau, which rises low the undulations of the ground, resistance would diminish the discharge. It was found possible, in Mr. Tower's phrase, to grade a line affording the regular inclination desired, and the close channel of masonry was adopted, with only two interruptions, the passage of the Haerlem river to reach the island, and that of the Manhattan valley in the island itself. The whole description of the conduct of this great work, thirty-eight miles in length, with its ventilators, culverts for streams, and roadways, as given in Mr. Tower's work, is full of practical information for the engineer; but the passage of most interest is that of the main difficulty of the scheme, the transit of the Haerlem river, a quarter of a mile in width. The plans suggested were various. An aqueduct bridge-an inverted syphon of iron pipes descending to a level near the river's surface, and passing along a stone embankment perforated by an arch sufficient for the passage of the stream-a suspension-bridge on stone piers, maintaining the regular inclination of the aqueduct, and supporting iron pipes-a low bridge supporting an inverted syphon of iron pipes. The latter was in the first instance adopted, and some progress made towards its execution, when the promoters were thrown back on their resources by an act of the Legislature, which required, either that the parties should tunnel under the river at a specified depth, or raise their structure on arches of eighty feet span and 100 feet elevation above the level of high water. They took counsel on this. The example of the Thames tunnel, though favoring practicability, was not encouraging on other grounds, and a fusion of the two plans, the syphon and the bridge more Romanorum, was preferred, and has been executed. Both here and in the Manhattan valley motives of economy have induced the architect to depart from the regular inclination of the stone channel. At Haerlem, Mr. Tower informs us :
To those who had watched over the work during its construction, and looked for its successful operation, this was peculiarly gratifying. To see the water leap from its opening, and rise upwards with such force and beauty, occasioned pleasing emotions, and gave proof that the design and execution were alike faultless, and that all the fondest hopes of its projectors would be realized. The scenery around this fountain added much to its beauty; there it stood, a whitened column rising from the river, erect, or shifting its form like a forest-tree as the winds swayed it, with the rainbow tints resting on its spray, while on either side the woody hills arose to rival its height. All around was nature; no marble basin, no allegorical figures wrought with exquisite touches of art to lure the eye, but a fountain where nature had adorned the place and mountain scenery.”—p. 112. with the grandeur and beauty of her rude hills
We cannot say that we consider 'rude hills and mountain scenery,' if such adorn the place,' as especially suited to set off the merits of an object so purely artificial; but we rejoice with Mr. Tower that Neptunes and river-gods were spared. We leave the waters we have now traced in the two vast reservoirs constructed in the city for their recep 'The distance between the extremes of the tion. Into the latter of these they were adpipes when laid across the bridge will be 1377 | mitted on July 4, 1842, and
with a pomp
in the a
ceremony fully justified by the occasion, al- will exceed the Roman work in utility. The ways presuming that none of Mr. Sydney following passage in Mr. Murray's HandSmith's money has flowed with them down book for Travellers in France' (one of the the arched culvert never to return. The best of his series), coming from an English whole cost of the work, exclusive of the engineer acquainted with the spot, will best future expense of detailed distribution, describe it :
amounts to nine million of dollars.
A highly-important hydraulic work has been tion under the able direction of M. de Montrichprojected, and is now in rapid progress of execu
The case of the Manhattan valley not inaptly illustrates an observation in perhaps the ablest work which has yet issued from an er. This canal will derive its water from the American pen, Mr. Prescott's 'Conquest of Durance, near to the suspension bridge at PerMexico.' Speaking of the great works of tuis, and this will be conducted by open cutting the Tezcucan monarchs, he says:- The and tunneling for a distance of 51 miles, through most gigantic monuments of architecture the a most mountainous and difficult country, until world has witnessed could never have been it will be employed for the supply of the city, as it reaches the arid territory of Marseilles, where reared by the hands of freemen.' The as well as for irrigation, and giving activity to varisertion contained in this pithy sentence may ous branches of industry, which require water perhaps admit of qualification. If permitted power. The section and fall of this canal is to amplify such a text of such an author, we calculated to pass 11 tons of water per second, should say that there are but two influences and its levels are so disposed, that this quantity which can generally avail to produce that of water will arrive near to the city, at an elevation of 400 feet, above the level of the sea. superfluous magnificence in construction of which Mr. Prescott is speaking:-the vanity attempted either in ancient or modern times 'Perhaps no work of this description has been of men who command the resources of sub-more hardy in its conception, or more really ject myriads, and that degree of religious en- useful in its effects. Three chains of limestone thusiasm which is not perhaps likely to be mountains are already nearly pierced by the 10 found among freemen' in Mr. Prescott's miles of tunnels which are required to conduct acceptation of the term, but which has co-vey it across the ravine of the river Arc (about 5 this stream; and an aqueduct, which is to conexisted with conditions of society far re- miles from Aix) is now in construction; its elemoved from servitude. The palace of the vation above the river will be 262 feet and its Tezcucan Alfred or David, shall we call him, length across the ravine 1230 feet. The design for he resembled both, and the Versailles of for this gigantic structure is in excellent taste, and Louis XIV., are samples of the one-the as a work of art, it will not suffer from compariremedieval cathedrals of the other. The val- son with the famous Pont du Gard, which it will ley of the Manhattan may serve to show that much surpass both in altitude and size. The esthe deliberate and voluntary contributions of this sum is raised by the city of Marseilles withmated cost of this canal is about 450,000l., and freemen cannot be relied upon for underout aid from the government. The revenue takings which the Agrippas of former times arising from this work will be principally from were able to execute. In our own time it supplying water for irrigation, as the value of will be much if the united efforts of Ger- land in such a climate is quadrupled if water can many, stimulated by a powerful and zealous be so applied to it.'-P. T* Sovereign, should carry out the unfinished
scheme of the Cologne cathedral, bequeathed Our English peculiarities of soil and clito them by a petty electorate. Altogether, mate are not such as to familiarize us with we are allowed calmly and not invidiously the merits of works of this class, which in to draw comparison between the Croton the early periods of civilization probably took aqueduct and the similar works of old Rome, precedence of the navigable canal, whether we shall perhaps conclude that with respect instituted for purposes of war or commerce. to the conveyance of water for consumption The canal of irrigation hardly ranks among modern skill has hardly attained any signal our greater public works, and in England has improvement upon ancient practice. The only been applied on a small scale by indi aqueducts of Rome remain not only un- vidual proprietors. Even here, however, a equalled in costly magnificence, but scarcely visit to the Duke of Portland's water meadsurpassed in practical attainment of their beneficent purpose.
ows at Clipstone in Nottinghamshire will furnish some conception of the efficacy which such works may possess in the arid climates
and soils of Southern Europe and the East.
We cannot, however, omit to mention a work now in progress in the old world, which, though its estimated expense be but a fourth of that of the Croton aqueduct, prom-will effect the purification of the port. The water *It is not expected that the canal of Marseilles ises in magnificence to rival the Pont du will be otherwise employed, and another plan for Gard nearly on its own ground, while it effecting this has been proposed by Mr. P. Taylor.
The power of Eastern despots has probably | Barbarians as they were, it is but justice to seldom been applied to such purposes with them as well as to their captive to add, that the systematic skill displayed by the English he owed his life on more than one occasion nobleman in question. It is, however, evi- to well earned feelings of good will and the dent that on works of this description were appreciation of his good offices towards them, based the resources and grandeur of dynas- which in his previous intercourse he had conties whose triumphs have long since shrunk trived to instil into their rugged bosoms. into a coin, of those forgotten Bactrian kings With reference to the application by man whose effigies have been dug up by the thou- of inland water to purposes of commercial sand by Mr. Masson and other recent travel-transport, modern superiority is more inconlers, as well as of the more modern Babers testable. The invention of locks alone has and Shah Jehauns. The remains of many of left Sesostris and Drusus at an immeasurable these great works, choked and neglected as distance. To men living in an age of steamthey are, have sufficed to disclose to the ob- engines and Daguerreotypes it may appear servant officers of our Indian army, the se- strange that an invention so simple in itself cret of the former wealth and population of as the canal-lock, and founded on properties districts now abandoned to sterility. Could of fluids little recondite, should have escaped the influence of British power have been the acuteness of Egypt, Greece, and Rome. consolidated either directly, or through the When we reflect, however, for how many medium of some docile sovereign, in the centuries the principle of the printing press plains of Affghanistan, a trifling outlay on lay dormant, yet alive, in the stamped brick the restoration of some of these works would of Babylon, and the signet-rings of kings and have sufficed to spread over those plains the senators, we shall cease to wonder. Some fertility they once enjoyed; and the mountain have supposed that locks were used, before chiefs are so dependent on the plain for their they were known to Europe, in China—that support, that their submission would have fol- vast repository of ideas partially carried out, lowed without the necessity of storming their and inventions unimproved; but it is not cer strongholds. A short time before the insur-tain, even if certain locks described by Nieurection against the British and Shah Souja hoff, a follower of a Dutch embassy in the broke out, one of our officers, Captain Drum-seventeenth century, were such as are in use mond of the Bengal cavalry, employed on a in Europe, that they were coeval with the mineralogical survey of Affghanistan, made construction of the canal, which dates from a report to the Envoy, strongly urging the 1289. We doubt whether at this time the measure of restoring a canal of irrigation in double-gated lock exists in China; but, if it the Kohistan district, north of Caubul, which does, we think it was probably introduced in the palmy days of the Bactrian empire had there by missionaries from Europe. In the watered the plain of Begram, one of the dis-article of embankment we might indeed postricts most remarkable for the evidences of sibly take a lesson of the Chinese. former wealth and population, but now an their canals carried through extensive lakes arid desert. The rumor of the project reach-by this contrivance have no parallel in Eued Meer Musjidi, one of the mountain chiefs, rope.
whose fastness commanded the neighboring In Europe the two great modern subsidia' valley of Nijerow, and who had been con-ries to inland navigation, the navigable aquespicuous among the most implacable oppo- duct and the lock, have been very generally nents of our arms. He was, however, de- ascribed to Italy and the fifteenth century. pendent upon Caubul for every supply, except By more recent authorities the lock has been that of corn and sheep alone, which the val-claimed for Holland. The first instance we ley under his control produced, and which can trace of the aqueduct is that of the canal he exchanged with the city for all other arti- of Martesana in the Milanese, which in 1460 cles of necessity. He was so alarmed at the was conducted over the torrent of Molgora by prospect of a new and intervening source of means of a bridge of three arches of some supply about to compete with that of his own thirty feet span. valley in the market, but also so attracted by It has been usually supposed that the doua hope of a share in the profits, that he imme-ble-gated lock was invented by the brothers diately sent in proposals of friendship and Domenico of Viterbo, and first applied by zealous co-operation in the project to the them in 1481. This supposition originates officer in question, who had planned a jour- with Zendrini-one among- the most distin ney to confer with him on the subject, when guished on the long list of Italian mathemati
the insurrection broke out which doomed Captain Drummond to a long and memora- Zendrini, born in 1679 near Brescia, ble captivity in the hands of barbarians. placed in 1720, by the united suffrages of
Ferrara, Modena, and Venice, at the head of some of the widest of them being purposely a commission of engineers appointed to settle closed up to low-water mark by sheet-piling, several important hydraulic questions between which (with the sterlings of framework, filled these conterminous states. Of all legislation retained the river navigable for some hours to with rubble-stones for protection of the piers) that for running waters is perhaps the most Richmond at high water, sometimes quite to difficult, whether it affect the rights of differ- Kingston. The next degree of improvement ent states or of subjects under one sovereign- was the introduction of modern locks, at first for ty. Let him who doubts this try his hand on distinction called pound-locks, wherein water a general drainage and bog improvement bill was impounded for the reception of the boat; for Ireland. Such an appointment speaks the and these pound-locks, improved by modern acacknowledged eminence of the man. Ven-curacy with side walls and convenient sluices, have not only rendered the Thames and most of our other English rivers navigable, but, by economizing the water requisite for the transit of boats shaped to the lock, have given rise and scope to canal navigation; that is, to water car riage where no river or stream existed or does
ice at the same time gave him the permanent
The word sostegno seems peculiarly applicable to the original contrivance, intended 'One of the most efficacious methods of com- rather to bear up and sustain the weight of pelling rivers to submit to navigation, when nat-water than to enclose and impound it. urally unfitted for it by reason of their rapid de- word conca, also in use in Italy, might appear scent, is that of sostegni. to answer more closely to our pound-lock; We cannot satisfy ourselves with a transla- it is, however, constantly used in the same tion of this word. In this particular passage sense as the simple sostegno. A scientific the word lock would answer the sense; but correspondent, whose opinion is entitled to in others it admits a more extended interpret- much deference, and who is disposed to atation, and may indicate almost any of the tribute to this country an early, perhaps an older contrivances by which water is alter-independent, application of the pound-lock, nately sustained and liberated, weir, lasher, partly founds that conclusion on the fact that &c. Such were the contrivances mentioned the English term lock is purely national. It by Mr. Telford as in use till lately on is, as he has suggested to us, not the Italian the Thames:sostegno or conca, the Dutch sluys, the 'The first expedient which occurred was to French écluse, but the Anglo-Saxon loc, enthrust the boat as nearly as possible to the rapid, closure; and he infers, if, as usually supposand having well fastened her there to await aned, we had borrowed the invention, we should increase of water by rain; and this was some- have borrowed the name. We are inclined to times assisted by a collection of boats, which, by doubt the force of this philological argument. forming a kind of floating dam, deepened the Our term is at least an exact translation of water immediately above, and threw part of the the Dutch sluys and the German schleusse, rapid behind themselves. This simple expedient was still in practice at Sunbury, on the which, whether to be traced through the Thames, since the beginning of the present cen- French écluse and Italian chiusa to the Latin tury; and elsewhere the custom of building claudo and cludo, or to the nearer source of bridges almost alwaye at fords, to accommodate the Teutonic schliessen, has the same significaancient roads of access, as well as to avoid the tion, to enclose, shut up. Till we have posdifficulty of founding piers in deep water, afford-itive evidence to the contrary, we shall be ed opportunity for improvement in navigating the rapid formed by the shallow water or ford; for a stone bridge may be formed into a lock or stoppage of the river by means of transverse timbers from pier to pier, sustaining a series of boards called paddles, opposed to the strength of the current, as was heretofore seen on the same River Thames where it passes the city of Oxford at Friar Bacon's Bridge, on the road to Abingdon. Such paddles are there in use to deepen the irregular river channels above that bridge; and the boat or boats, of very considerable tonnage, thus find passage upwards or downwards, a single arch being occasionally cleared of its paddles, to afford free passage through the bridge. In this sense of the word, the arches of old London Bridge were designated as locks,
inclined to believe that the pound-lock came to us through Holland in the seventeenth century, and that the word lock, loc, or lokke, when used before this period, signified nothing more than the sostegno did in Italy previously to the fifteenth century. Zendrini
'By means of these (sostegni) even rivulets can be made available for boats; and this not only on level plains, but even in hilly countries. For this reason their inventor has certainly great claims of merit on society at large. I have made much research to discover his name, and to certify the date of so valuable a discovery, but without success, unless certain information, derived
from private papers, afford some light towards recognizing the meritorious contriver. I have found then that Denis and Peter Domenico, brothers, of Viterbo, acquired in 1481, September 3d, from Signor Contarini a certain site in the bastion of Stra, near Padua, in order to form in it a channel from the Piovego, the canal which comes from Padua to the aforesaid place, Stra; and in a certain memorial from these brothers, dated the same year, calling themselves Maestri di Orologgio, they set forth that they will enable boats and barges to pass through the sluice of Stra without danger, without being unloaded, and without being dragged; contriving at the game time that the waters shall issue with facility.... To these then, at least within the Venetian states, we may ascribe the honor of this invention, not finding any one else who had previously conceived or put in practice the idea.'
So far, then, we have Zendrini's opinion that the achievement of lifting or lowering a loaded vessel, without traction, from one
water level to another, was first accomplished by the brothers of Viterbo, though he gives it with some hesitation. This opinion, embraced by many, derived for a time confirmation from its adoption by Frisi.
Frisi was born at Milan in 1729, and having obtained an European reputation for his illustrations of the sublimest branches of the Newtonian philosophy, gave much of his attention to hydraulics. He travelled more than is usual with men of his pursuits and ecclesiastical profession; and in the latter period of his life made himself in England personally acquainted with the works of Brindley.
We have not seen the two earlier editions of Frisi's book on navigable canals published in 1762 and 1770;-but it is plain from the translation by Major General Garstin, that at that period Frisi fully concurred in the views of Zendrini. Frisi, however, revised and republished his work in 1782; and from some passages of this last edition it is clear to us that he had then found reason to change his opinion, and to ascribe the invention to a greater man than either of the brothers of Viterbo.
nolo, twelve miles distant-the first to dam up
of the invention, and some peculiarities of
the Brenta :
'The construction of these sostegni, and the
communication between our two canals were
Venturi, a more recent writer, and one of scarcely less repute than the two above quoted, throws back the invention to an earlier period. He writes:—
'It has been said that Vinci was the inventor of the double-gated lock, that ingenious machine which has opened so many issues to internal commerce among the moderns. But it is not he who first imagined them. The Venetians had constructed some on the Piovego in 1481; and Philip Maria Visconti had caused some to be executed about 1440. I believe that some were constructed even in the fourteenth century.'
'The ancients,' he says, 'understood the method of moderating the excessive descent of rivers. of maintaining the necessary supply of water, of absorbing it into reservoirs, and using it both for the defence of places and the irrigation of country, by means of certain sluices, which could be lifted up for the passage of boats. Belidor has described them in the 4th book of his "Architectura Idraulica." These had no spaces divided off in their interior, and were of the kind called Conche piane. Such precisely were the two sostegni commenced in 1188 and finished in 1198, under the direction of Alberto Pitentino, The quotation from the 'Rerum Italicarum architect; the one before the gate of Mantua, Scriptores' of Muratori, on which Venturi called the Cepeto gate, and the other at Gover-seems to rely for the achievements of Vis