DESCRIPTION OF THE LINE OF AQUEDUCT.
The dam, built to form the Fountain Reservoir, is about six miles above the mouth of the Croton River. The reservoir forms a beautiful sheet of water in the lap of the hills in the wild region of the Croton, and has received the name of the “Croton Lake.”
Pine’s Bridge over the Croton River, which is mentioned in the early history of the country, occupied a position which is now about the middle of this Reservoir, and there is at that place a bridge over the Reservoir resting upon piers and abutments.
The hills which bound the Croton Valley where the Reservoir is formed are so bold as to confine it within narrow limits: for about two miles above the dam the average width is about one eighth of a mile; at this distance from the dam the valley opens so that for the length of two miles more the width is about a quarter of a mile; here the valley contracts again and diminishes the width until the flow line reaches the natural width of the River at the head of the lake. The country immediately contiguous to the shore has been cleared up, and all that would be liable to impart any impurity to the water has been removed. This gives a pleasing aspect to the lake, showing where the hand of art has swept along the shores leaving a clean margin. Retiring from the water are the richly cultivated slopes with the neat farm houses overlooking the lake, or the hills crowned with forest trees, while at intervals a valley or ravine opens and empties in its tributary stream.
[Plate IX]. is a view taken above the dam showing the position of the entrance to the tunnel which leads from the Reservoir to the gate chamber at the head of the Aqueduct. The entablature which is seen on the left against the rock, is built directly over the mouth of the tunnel, and from this the tunnel extends through the rock to the gate house, which is seen on the right of the picture and some distance from the dam. The structure which is seen in the centre of the picture and on the ridge of the dam is a gate house over a culvert which extends through the body of the dam; this culvert is 30 feet below the surface of water when the Reservoir is full, and has gates which are operated by means of rods which rise to the interior of the house. During low stages of the River the water which is not drawn off by the Aqueduct may pass through this culvert and allow none to pass over the dam.
The entrance to the tunnel is protected by a screen of timber work.
[Plate X]. is a representation of the entablature over the mouth of the tunnel, showing the inscriptions upon it, relating to the date of the commencement of the dam and its completion, the persons who had contracts for building it, and those having charge of the work during the time.
X
ENTRANCE TO THE CROTON AQUEDUCT
COMMENCED 1837
COMPLETED 1842
[Plate XI]. is a view taken from a point below the dam and shows the relative positions of the dam and the gate chamber at the head of the Aqueduct.
The original channel of the River where the dam is built, was about 120 feet wide; the average depth of water at this place was about 4 feet; and the greatest depth 10 feet.
The left bank of the river arose abruptly with rock, the channel was gravelly, and on the right bank a sandy table land about 3 feet above the ordinary surface of water extended about 80 feet; then a sandy hill arose on a slope of about forty-five degrees.
In making the plan for a dam at this place it was determined to fill the main channel and the table land on the right bank with an embankment of earth; and on the left bank where rock was found, to build a body of masonry against the slope to the requisite height for the surface of the Reservoir and connect it with the embankment in the channel; this masonry formed the overfall for the water, and the rock in the side of the hill adjacent to it was excavated down to the level of the overfall, thereby extending it into the hill, making the space for the water to pass over partly of masonry and partly of rock. The embankment extended with a slope on the upstream side giving it a broad base, and the lower or downstream side was faced with a heavy wall of stone. There was a timber pier constructed in the embankment extending across the channel and faced with plank on the upstream side. The overfall was made of such length as was thought sufficient to pass all the water of the river during its highest stages, and with the view of adapting it to such purpose, examinations were made to find the highest marks of floods on the banks of the river; and those who were engaged in determining these marks were guided also by the observations of the inhabitants of the vicinity who had long known the river in its various stages. High freshets were witnessed during the construction of the work, for in the course of two years that the work was going up, all the various changes and freshets of rainy seasons were experienced, and those in charge of it did not neglect to note the quantity of water flowing on such occasions.
XI
F. B. Tower.
Gimbrede. sc.
VIEW BELOW THE CROTON DAM.
With such opportunities to become acquainted with the changes of the stream they could not fail to know the quantity of water flowing at periods of the highest freshets, and knowing it, to adapt an overfall of sufficient capacity for its discharge. For this purpose it was thought ample provision was made; yet at the time when the work was nearly completed such a flood occurred as could not have been anticipated from previous knowledge of the River; the water filling the entire passage at the overfall, flowed over the top of the embankment where it was not supposed it could ever reach. The lower slope of this embankment was covered with a wall not calculated to resist the action of the water and it gave way; the water broke through the embankment and rushed along the valley with most disastrous consequences. The breach occurred at an early hour in the morning; and many persons were suddenly aroused from their sleep to escape before the approaching waters. Dwelling-houses and mills were carried away and three lives were lost. Two of those who were drowned had taken refuge in the tops of trees, but these being swept away they were drowned; while others who were not able to reach the main land, but had also taken refuge in trees, were saved. The change wrought by the flood, in the appearance of the country, was truly wonderful and the destruction was complete. Night had closed over that valley where all was happiness and quiet, but day opened upon a scene of desolation. The fertile fields were torn up and covered with masses of stone and gravel, and the flood left marks of its fury far up on the hill sides.
At the commencement of the rain which caused this flood, the ground was covered with snow to the depth of eighteen inches: the weather became warm and the powerful rain storm continued incessantly for forty-eight hours. Notwithstanding the immense volume discharged at the overfall of the dam, the water was rising, during the night previous to this disaster, at the rate of fourteen inches per hour over the Reservoir, covering an area of four hundred acres.
It occurred on the 8th of January, 1841.
In repairing the breach it was decided to build an extension of solid hydraulic masonry in the place of the portion of embankment which was carried away.
The gate house and wing wall, which is seen on the ridge of the dam, shows where the masonry of the original structure connected with the embankment which extended across the river. The whole length of the overfall is 251 feet. Access to the house over the culvert, is gained by a foot bridge which is seen in the picture. The masonry of the original structure has a rock foundation, and the extension of the overfall which is seen on the left of the house extending across to the embankment has an artificial foundation of concrete.
The masonry of the dam is about 8 feet thick at the top and 65 feet at the base; it is built in a vertical form on the upstream side, with occasional offsets, and the lower face has a curved form such as to pass the water over without giving it a direct fall upon the apron at the foot; this apron is formed of timber, stone, and concrete; and extends some distance from the toe of the masonry, giving security at the point where the water has the greatest action. A secondary dam has been built at a distance of 300 feet from the masonry in order to form a basin of water setting back over the apron at the toe of the main dam so as to break the force of the water falling upon it. This secondary dam is formed of round timber, brush wood, and gravel; it may be seen in the picture directly under the bridge which extends across below the main structure.
On the upstream side of the masonry of the dam, an embankment of earth is filled in, extending 275 feet from the masonry at the base, and extending from the masonry with a slope of 1 foot in 5 on the top.
XII
F. B. Tower.
W. Bennett.
CROTON AQUEDUCT AT SING SING.
The whole work about the dam possesses great interest, and though it be distant from the city and somewhat difficult of access, will not fail to please those who may take time to visit it. Just above the place where the dam is constructed the River had a bold turn and flowed along at the foot of a steep and rugged bank. A road passed along at the base of this hill leading to a mill which was situated at the turn of the River, before mentioned; a substitute for this road, which was submerged, has been made along the hill side passing on the right of the gate house. Enough of the forest has been cleared away to admit of the construction of the work, but the place still possesses much of its original wildness, and to see such beautiful mechanical work standing against the rude rocks,—to observe what changes have been wrought in the form of this rock to render it subservient to the purposes of the work, makes us feel that there has been a strife there; but it all shows that art has gained the ascendency.
The form which has been adopted for the face of the extension of the overfall is a reversed or double curve which would be easily recognized as Hogarth’s line of beauty: the overfall for the original dam has a plane face with a curve at the base.
Walks are formed about the work bordered with grass, giving a neatness and finished appearance to the whole; and every thing in connection seems to indicate that the vicinity of the Croton Dam will be one of the resorts in summer seasons for the citizens of New-York. From the Croton Dam the Aqueduct passes along the left side of the valley of the Croton River until at the mouth of this river it reaches the left bank of the Hudson, which it pursues, keeping at a distance of nearly half a mile from the River, until it arrives at the village of Sing-Sing, which is eight miles from the dam. In the course of this distance the Aqueduct passes through four tunnels and encounters many valleys and ravines where high foundation walls were required, and culverts for the passage of the streams.
At the village of Sing-Sing there are two Aqueduct bridges; one over a public road-way, and the other over the Sing-Sing Kill. These bridges and the adjacent work form a very interesting point on the line of Aqueduct.
[Plate XII]. is a view of the Aqueduct at this place: at the left of the picture may be seen the bridge over the road, and on the right that over the Kill. The bridge over the road has a span of 20 feet, and the direction of the road-way being not at right angles with the line of Aqueduct required the arch to be built askew; the arch lies in the direction of the road-way, having the ends in planes parallel with the direction of the Aqueduct. This bridge is worthy of notice, but public attention is more generally directed to the larger one: that has an arch of 88 feet span and a rise of 33 feet; the form of the arch is elliptical, being a compound curve drawn from five different centres, or radius points. The Kill, or valley over which this arch stands, is a deep narrow gorge worn by a small stream which empties into the Hudson River.
The bottom of the ravine is about 70 feet below the soffit or under side of the arch. [Plate XIII]. is another view of the large arch taken from the bottom of the valley near it, and shows the bridge which has been constructed for a public road passing under it, and the mill near by.
XIII
F. B. Tower.
Napoleon Gimbrede. sc.
AQUEDUCT BRIDGE AT SING SING.
This arch presents a singularly bold appearance, vaulting over the roadway and rising high up above the old mill, and what adds much to this boldness, is the narrowness of the arch, or small distance from one end of it to the other; being only 23⅓ feet long at the springing line while the span is nearly four times this length. The length of the arch diminishes towards the crown, the ends being in planes not vertical, but inclining towards each other at the top. Each end has a batter or inclination of one twenty fourth of its height, or half an inch to the foot. The arch is built of granite, is 3 feet thick at the crown and 4 feet at the spring or base. The abutments have a foundation of solid rock which was excavated in proper form to give them firm footing. The whole structure presents a degree of stability which seems to defy the effects of time. The Aqueduct has a cast iron lining over this bridge (as it has over all of this character): it is formed of plates five eighths of an inch thick, put together with screw-bolts and nuts and the joints closely filled with iron cement. This lining is within the brick work of the bottom and sides of the channel-way, having four inches of brick outside of it and four inside. The object of it is to prevent any water dripping through the work, lest by any means it should fill the exterior masonry of the bridge with moisture and thus render it liable to injury from frost. Other precautions are taken in forming the masonry about the channel-way, to prevent this exuding, and the whole plan of the work shows foresight and precaution worthy of the highest praise.
From the Sing-Sing Kill the Aqueduct pursues a course along the east bank of the Hudson and the first work of peculiar interest is the Aqueduct bridge over the road from Tarrytown to Sing-Sing; before it reaches this place it passes through three tunnels, over high foundation walls, and encounters deep excavations.
XIV
F. B. Tower.
W. Bennett. sc.
AQUEDUCT BRIDGE FOR ROAD WAY.
[Plate XIV]. is a view of this bridge: it is eleven and a quarter miles from the dam. The arch is 20 feet span and has a versed sine or rise of 5 feet. From this the Aqueduct passes on, encounters one tunnel, and reaches the valley of Mill River, twelve miles and three quarters from the dam. This River runs through Sleepy Hollow and enters the Hudson about a mile and a half above Tarrytown. The stream is 72 feet below the bottom of the Aqueduct, and the valley being of considerable width required a very heavy foundation wall.
[Plate XV]. is a view of the Mill River Culvert: it is 25 feet span and 172 feet long. It is about half a mile east of the road leading from Tarrytown to Sing-Sing, and to follow the course of the stream which passes through it, it is three quarters of a mile to the Old Dutch Church, near Tarrytown, which is well known, and familiar to every one who has read Irving’s “Legend of Sleepy Hollow.”
There is much of the wildness and beauty of nature about this place; the woods are standing close upon the work,—the stream which passes through the culvert displays its whitened crests as it tears along over the rocky bed, and utters its music until it is lost in the depth of the forest. The wild vines will soon climb the walls and cover them; vegetation will gather over the work until nature and art be harmoniously wedded.
XV
F. B. Tower.
W. Bennett. sc.
CROTON AQUEDUCT AT MILL RIVER.
From Mill River the Aqueduct passes the village of Tarrytown and through one tunnel and over several depressions and streams, reaching Jewell’s Brook which is seventeen and a half miles from the dam. This stream enters the Hudson River about two miles below Tarrytown. The distance from the mouth of the stream to the line of Aqueduct is only a quarter of a mile.
[Plate XVI]. is a view of the work at Jewell’s Brook. The culvert for the stream is 6 feet span and 148 feet long. The larger culvert for a private road is 14 feet span and 141 feet long. The wall which supports the Aqueduct at this valley is 50 feet high.
In this case, as in many others, the slope wall which covers the face of the embankment has an arch turned in it over the top of the culverts: the object of this is to prevent the direct pressure of the wall upon the top of the parapet wall, as it would tend to displace the coping or injure the parapet itself.
XVI
F. B. Tower.
J. W. Hill.
CROTON AQUEDUCT AT JEWELLS BROOK.
After crossing Jewell’s Brook the Aqueduct passes along the bank of the Hudson through the village of Dobb’s Ferry, where there is a tunnel and a valley requiring a culvert, and continues from this place to the village of Hastings, where there is an Aqueduct bridge over a rail-road which is used for transporting marble from the quarry near by, to the landing on the Hudson River.
[Plate XVII]. is a view of this bridge and the view under the arch shows the face of the quarry which is near the work; the landing at the river is near by, giving a very rapid descent from the quarry. The arch has a span of 16 feet and a rise of 1½ foot. This bridge is twenty-one miles from the dam.
From Hastings the Aqueduct continues along the bank of the Hudson until it reaches the village of Yonkers where it leaves the valley of the Hudson, and passing through a tunnel of considerable length reaches the valley of Saw-Mill River. At the crossing of this valley there is a culvert of 20 feet span for a public road to pass under the Aqueduct, and one having two arches each 25 feet span for the river.
[Plate XVIII]. is a view of the work at Saw Mill River.
The water is set back at this place by a dam for a mill a short distance below, giving the stream an appearance of more magnitude than it really possesses. This point is 25 miles from the dam. The wall which supports the Aqueduct over this valley is 40 feet high.
From Saw-Mill River the Aqueduct passing through one tunnel soon reaches Tibbit’s Brook, which it crosses by means of a foundation wall about 30 feet high and a culvert of 6 feet span, and continues along the south side of the valley of this brook, thence to the Harlem River which it crosses at one mile from McComb’s Dam. This crossing is thirty-three miles from the Croton Dam, and about ten miles from the City-Hall.
The distance across this valley is about a quarter of a mile, and the surface of the River is 120 feet below the bottom of the Aqueduct.
In all the examinations which were made with a view of bringing water from Westchester County, the crossing of this River, or arm of the sea, was regarded as the most formidable work that would be encountered; various plans were proposed, and in presenting these plans the project was such as to call into requisition much talent and skill.
An Aqueduct Bridge built of stone, having arches resting upon piers and abutments, was proposed so as to continue the Aqueduct across with its regular inclination.
An Inverted Syphon of iron pipes was proposed; the pipes to descend to a level near the surface of the River, and passing along upon a stone embankment rise again and connect with the Aqueduct: in this stone embankment an arch was to be built of sufficient dimensions to allow free passage of the water of the River.
XVII
F. B. Tower.
J. W. Hill.
CROTON AQUEDUCT AT HASTINGS.
Another plan was proposed which, though novel in its application to such purpose, was worthy of consideration: this was to build a Suspension Bridge of wire cables reaching across the valley, supported at intervals upon suitable stone piers. This, maintaining the regular inclination of the Aqueduct, would support iron pipes. The design was a bold one, yet instances where such bridges have been constructed for road-ways afford examples of the feasibility and permanency of the structures, and prove that the application of that principle for this purpose was not a visionary project.
The plan which was adopted as the most suitable under all the considerations of economy and security to the work, was a Low Bridge to support an inverted syphon of iron pipes; and the design of it was as follows: adjacent to the southern shore of the river there was to be constructed an arch for the channel of the river, of 80 feet span and springing from abutments 10 feet above high water level; this would form a passage of 80 feet wide, and the height from high water level to the under side of the arch at the crown would be 50 feet: south of this arch followed three other arches on the slope of the rocky hill, of 35, 30, and 25 feet span: south of these arches a foundation wall was designed to continue the plane of inclination to the level of the Aqueduct. From the large arch to the northern shore of the river an embankment of stone was designed for the support of the pipes, and from this wall the table land on the northern shore and the slope of the northern side of the valley, would be excavated to a form to give the proper position to the pipes descending from the Aqueduct. The lowest level of the top of this stone embankment was designed to be 4 feet above flood tide. Suitable parapet walls were designed to be built along the sides of the embankment to sustain a covering of earth over the pipes. With the form which was given to this inverted syphon, four pipes, each of 3 feet interior diameter, were found to give a discharge of water equal to that of the Aqueduct of masonry on the established inclination.
In accordance with this plan of the Low Bridge the work for crossing the River was put under contract and some progress made in its execution, when a law was passed by the Legislature of the State requiring, instead of this, a structure, the arches of which should be (over the channel of the river) at least 80 feet span and having a distance of 100 feet from the level of high water to the under side of the crown; or to go under the channel of the river by a structure which should not rise above the bed, and that would leave the present channel unobstructed. At this time when the work was going on vigorously, they were compelled to abandon the plan which had been adopted, and devise one which would comply with the requirements of the law of the Legislature. A comparison was instituted between the plan of a tunnel under the bed of the river and that of a bridge of masonry at the required height above the river.
The tunnel would be at least 300 feet long and the top of the masonry forming it, would be 18 feet below high water level. In this tunnel the iron pipes would pass under the River and would be protected from the salt water.
XVIII
F. B. Tower.
W. Bennett. sc.
CROTON AQUEDUCT AT YONKERS.
An estimate of the cost of crossing by means of each plan was made, and the result was in favor of the tunnel under the bed of the River; but from the imperfect knowledge which could at best be obtained of the formation of the bed, there was great uncertainty in the estimate of the cost of the tunnel and the time that would be required for its completion. The history of the progress of work in the tunnel under the Thames at London warned them of the difficulties of such a work and the uncertainty of arriving at a proper estimate of the cost.
In the alternative to which they were driven by the Act of the Legislature, the plan of an Aqueduct bridge of masonry was adopted as the proper one for crossing the River; but in establishing its altitude they complied only with the requisitions of the law, and made the soffit or under side of the arches at the crown, 100 feet above common high water level. This would not carry the work up to the level of the Aqueduct, and would render it necessary to connect the Aqueduct on each side of the valley by iron pipes which would descend to the level of the bridge and crossing it rise again to the masonry channel-way. The plans which were before spoken of for a bridge of masonry across this valley, contemplated a structure which would maintain the regular inclination of the Aqueduct; and the channel-way would have been formed of masonry having a cast iron lining; but a more full consideration of the subject suggested the propriety of using iron pipes over the bridge, even if it had been carried up to the grade plane of the Aqueduct: when the use of iron pipes was determined upon, then considerations of economy induced them to build the work only high enough to comply with the requirements of the law.
The plan which has been adopted for building an Aqueduct bridge across this valley is as follows: on the south shore of the river there is one arch of 50 feet span, across the river there are eight arches, each of 80 feet span, and on the north shore there are six arches each of 50 feet span; making a range of fifteen arches. From the extremes of this range of arches, a foundation wall of dry stone work connects with the Aqueduct.
Two of the piers in the river have a rock foundation and the foundations for those where rock is not obtained is formed by driving piles which are placed 2½ feet from centre to centre, and the spaces between filled with concrete to a depth of 3 feet below the top of them.
[Plate XIX]. is a view of this bridge, which, when completed, will be the most interesting work on the whole line of Aqueduct, and in its appearance will rival the grandeur of similar works of the Ancient Romans. The height from the foundations in the river, to the top of the work is 150 feet; the width across the top is 21 feet. The pipes when laid upon the bridge will be covered with earth to protect them from frost. The distance between the extremes of the pipes when laid across the bridge will be 1377⅓ feet. For a distance of 18 feet at each end of the pipes there is an inclination and the remainder of the distance across, which is 1341⅓ feet, they are level.
The bottom of the interior of the pipes on the level part, is 12-8/10 feet below the bottom of water way of the Aqueduct on the north side, and 10-5/10 below that on the south side of the valley.
In the progress of excavating in one of the coffer dams in the channel of the river a portion of a sunken vessel was found within the enclosure; it had the appearance of great age. Tradition among the inhabitants of the vicinity says that at an early period of the Revolutionary war a vessel was scuttled and sunk in that part of the river.
XIX
F. B. Tower.
Napoleon Gimbrede. sc.
CROTON AQUEDUCT AT HARLEM RIVER.
To a mind fond of antiquarian researches and accustomed to invest objects of such a nature with associations of the past, this ancient wreck would furnish a fruitful theme. We are now laying the foundation of a magnificent work: at the day when this vessel was sunk the American people were laying the foundation of a new form of government composed of principles which should support a fabric of enduring strength and beauty. We are now building a work which will stand as a monument of the genius and enterprise of the age, but it may be regarded among the fruits of that civil and religious liberty which has been reared upon the foundations formed by the people of that day.
The water is now conveyed across this valley by an iron pipe of 3 feet interior diameter. In the progress of preparing foundations for the piers of the bridge, an embankment has been formed across the River and the pipe leaving the Aqueduct on the north side of the valley follows down the slope of the hill, and crossing over the River upon this embankment, ascends on the south side again to the Aqueduct. At the bottom or lowest point in this pipe, a branch pipe of 1 foot diameter has been connected, extending a distance of 80 feet from it at right angles and horizontally: the end of this pipe is turned upwards to form a jet, and iron plates are fastened upon it giving any form that may be desired to the water issuing. The level of this branch pipe is about 120 feet below the bottom of the Aqueduct on the north side of the valley; affording an opportunity for a beautiful jet d’eau;—such an one as cannot be obtained at the fountains in the city. From an orifice of seven inches diameter the column of water rises to a height of 115 feet when there is only a depth of 2 feet of water in the Aqueduct.
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 this opening and rise upwards with such force and beauty, occasioned pleasing emotions and gave proof that the design and construction of the work 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, or waving like a forest tree as the winds swayed it, with the rainbow tints resting upon its spray, while on either side the wooded hills arose to rival its height: all around was of 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 with the grandeur and beauty of her rude hills and mountain scenery.
[Plate XX]. is a distant view of the jet at Harlem River.
From Harlem River the Aqueduct passes along the south bank of the River for a short distance where it rests in the side of the rocky hill, and continues over an uneven surface encountering two tunnels before it reaches Manhattan Valley, which is about 35 miles from the Croton dam. This valley is four fifths of a mile wide where the Aqueduct meets it, and the depression is 102 feet below the plane of Aqueduct grade.
XX
F. B. Tower.
W. Bennett.
VIEW OF THE JET AT HARLEM RIVER.
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 forbade it. Where the Aqueduct reaches the north side of the valley, a gate chamber is formed, and from this, two pipes of 3 feet interior diameter descend to the bottom of the valley and ascend on the south side to another gate chamber where they connect with the Aqueduct again. Provision is made for four pipes of 3 feet diameter, but at present only two are laid which answer the demands of the city at this time. At the bottom of the valley waste cocks are provided which discharge into a sewer leading to the Hudson River, a distance of half a mile.
The lowest point in the pipes is 102 feet below the bottom of the water way of the Aqueduct on the north side of the valley.
From Manhattan Valley the Aqueduct passes through a tunnel, and following its course the next work of interest is at Clendinning Valley, which is thirty-seven miles from the Croton Dam. This valley is 1900 feet across, and the Aqueduct is supported upon a foundation wall of dry stone work having the face laid in mortar, except over three streets where bridges are built, having an arch of 30 feet span for the carriage-way and one on each side of 10½ feet span for the side walks. These bridges are over 98th, 99th, and 100th streets.
XXI
F. B. Tower.
W. Bennett. sc.
CROTON AQUEDUCT AT CLENDINNING VALLEY.
[Plate XXI]. is a view of a portion of the work at Clendinning Valley showing the three bridges; and comprises a length of about 700 feet.
The greatest height from the foundation to the top of the work is 50 feet, and the width at the bottom of the Aqueduct is 30 feet. Parapet walls are built on the sides of the wall above the bottom of the Aqueduct to support a covering of earth over it.
[Plate XXII]. is an enlarged view of one of the bridges and a portion of the foundation wall and Aqueduct adjacent to it. The Aqueduct has a cast iron lining over the bridges like that described at the Sing Sing Kill.
These bridges are beautiful specimens of mechanical work; indeed the whole structure across this valley has a degree of neatness, finish, and taste, not surpassed by any on the line of Aqueduct.
To visit this structure and follow along its whole extent, gives one an idea of the magnitude of the work which the City of New-York has accomplished; particularly when it is considered that this is only one of the parts which make up the whole.
From Clendinning Valley the Aqueduct soon reaches the Receiving Reservoir which is thirty-eight miles from the Croton Dam.
This Reservoir occupies an elevated part of the island between 79th and 86th streets and between the 6th and 7th Avenues. It covers seven of the city blocks; is divided into two divisions, one covering three and the other four of these blocks. It is 1826 feet long and 836 feet wide from outside to outside of the top of the exterior walls of the embankment, making an area of thirty-five acres.
XXII
F. B. Tower.
Gimber.
AQUEDUCT BRIDGE AT CLENDINNING VALLEY.
The situation was chosen as one affording the proper elevation: but its formation was such as to present difficulties in the way of making the Reservoir perfectly water-tight; the surface, in tracing it from 79th to 86th street, was quite undulating, a portion of it in the southern division of the Reservoir falling below the proposed bottom, and that portion of the surface which was earth, forming only a covering to the rock, which over the whole island, presents a singularly broken and uneven formation. In almost every instance of excavation, the rock was found above the proposed bottom of the Reservoir, and the difficulty of preventing leakage along the surface of this rock may easily be conceived; but considering that measures are taken to prevent such an occurrence, another difficulty is still presented in the formation of the rock: the veins and fissures which are frequent in this gneiss formation would possibly afford courses for the water to escape; the rock being unsound in many instances, would render such an occurrence still more liable. A Reservoir has however, been constructed here which proved, when it was filled with water, that sufficient precaution was used to prevent leakage, and that the difficulties which presented themselves before the commencement of the work were no longer to be feared.
The embankments forming the Reservoir are made of good assorted earth, and a portion of the bank is puddled, or made compact and impervious by wetting the earth and using a spade to force it into a compact state. They are about 20 feet wide on the top, and increase in thickness towards the base by a slope on both sides: the outside face of the Reservoir bank has a slope of 1 foot horizontal to 3 feet vertical: the inside has a slope of 1½ foot horizontal to 1 foot vertical. The outside face is protected by a stone wall 4 feet thick having the face laid in mortar: the inside face is protected by a slope wall of stone laid without mortar, 1¼ foot thick. The top of the bank is 4 feet above top water line, and the inside slope wall terminates at 2 feet above top water line, leaving the remainder of the face to be covered with grass, so as to present a belt of green above the water on the bank entirely around the Reservoir.
A neat fence bounds the outside and the inside of the top bank, forming a walk of a mile in length around the entire Reservoir.
The greatest depth of water in the northern division is 20 feet: it was originally intended to excavate so as to give the water a depth of 20 feet over the whole, but a quantity of rock was left, as the capacity was thought to be sufficient without taking it out.
The southern division has 30 feet of water where the bottom was filled in with embankment, and 25 where excavation was made. A portion of rock was left in this division for the same reason as that in the northern division; the greater part of it being in the south-west corner, where it rises above top water line.
The capacity of the Reservoir when both divisions are full, is 150,000,000 Imperial gallons.
The surface of water in the northern division covers 18.13 acres, and in the southern division, 12.75 acres; making in both nearly 31 acres.
[Plate XXIII]. is a plan of the Receiving Reservoir.
The Aqueduct enters a gate chamber at A. where there are regulating gates by which the water can be discharged into the northern division; or into the southern division by a continuation of the Aqueduct within the Reservoir bank to the angle B. of that division.
XXIII
Scale 200 feet to one inch
F. B. Tower.
Gimber.
RECEIVING RESERVOIR
A connection pipe of cast iron is placed in the division bank at C. to allow the water to flow from one division into the other in order to equalize the level; it is placed 10 feet below top water line and has a stop-cock to close or open it.
At D. is a waste weir, where surplus water may pass off: it is so arranged that the water, when it rises to a proper level, will flow into a well, and from this a brick sewer conducts it off into low grounds, where it finds its way to the East River.
At each place where it is designed to discharge water from the Reservoir, a gate house is built far enough into it to reach the greatest depth of water beyond the slope of the embankment. These houses have a wall upon three sides, and the front which faces the centre of the Reservoir has a suitable screen of wood work and wooden gates which regulate the level below the surface for the current of discharge, and the iron pipes leading from these houses have a stop-cock by which the discharge is controlled; this stop-cock is in a vault within the Reservoir bank.
The position of these effluent gate houses is marked on the plan by the letters E, F, G, H, there being two in each division. A foot bridge affords convenient access from the bank to the house.
Those houses on the east side denoted by E, F, are the ones from which pipes lead to the lower or Distributing Reservoir, and those on the west side denoted by G, H, are intended for supplying the western part of the city north of the Distributing Reservoir.
There is a vault within the eastern bank to accommodate the pipes which leave the house E, and passing along, connect with those from the house F, and thence the pipes continue along 80th street and the 5th Avenue to the Distributing Reservoir. A vault within the west bank accommodates the pipe which leads from the house H, and intersects the one from G, passing out at 81st street; thus in this street a pipe draws from the southern division at G, and a branch of it passing along within the vault draws from the northern division at H.
Provision has been made on the east side of the Reservoir for supplying that part of the city when it becomes necessary.
At present there are two pipes leading from this to the Distributing Reservoir, each 3 feet interior diameter, and they are arranged that both may draw from the southern division, or one from that, and one from the northern division. The pipes are placed at a level below the bottom of the division from which they draw: the bottom of the interior of those from the southern division being 2 feet below, and that of those from the northern 5 feet below.
The exterior walls of this Reservoir present a face of rough-hammered masonry, finished in a manner to give them neatness and durability.
As a specimen of mechanical work, this Reservoir will not bear a comparison with the lower, or Distributing Reservoir, yet the sheet of water it presents, renders it an object of perhaps greater interest. This beautiful lake of pure water resting upon the summit of the Island is truly a pleasing object, and considering its size, is what no other city can boast of having within its limits.
The Distributing Reservoir is situated on the west side of the 5th Avenue between 40th and 42nd streets; it is two miles from the Receiving Reservoir, and about three miles from the City-Hall.
XXIV
F. B. Tower.
Napoleon Gimbrede. sc.
DISTRIBUTING RESERVOIR.
The question may naturally be asked, why this Reservoir was built, when the receiving one, of such great capacity, is so near at hand? The reason for building it, was to obtain an efficient head of water near to the densely populated parts of the city, and had the formation of the island been favorable, the Receiving Reservoir would undoubtedly have been located farther down, bringing the store of water more nearly in the centre of the city.
[Plate XXIV]. is an isometrical view of the Distributing Reservoir showing the front on the 5th Avenue and on 42nd street.
The pipes which leave the Receiving Reservoir follow along the 5th Avenue until they reach 42nd street, where they turn and enter the Distributing Reservoir at the base of the central pilaster in that street, which in the drawing is shown on the right hand side. The pipes enter at the bottom of the Reservoir and the flow of water is regulated by stop-cocks: the door in the pilaster affords an entrance to the vault where these stop-cocks are situated. The Reservoir is divided into two separate divisions by a wall. It is designed to have three pipes, each 3 feet diameter, to lead from the Receiving to the Distributing Reservoir and arrangements are made to discharge water from two of them into one division of the Distributing Reservoir at a time, or the water may be divided into an equal supply for both divisions.
On the south side of the Reservoir a pipe of 3 feet diameter leaves each division and they are arranged with branches so as to draw from one or both divisions. The house standing across the division wall is directly over the mouth of the effluent pipes, and is constructed like those at the Receiving Reservoir, with a gate and screen frame of timber. The central pilaster on 40th street has an entrance (like that on 42nd street) to the vault where the stop-cocks are situated which regulate the discharge from the Reservoir. The pipes leave the Reservoir at the base of this pilaster and from 40th street, curve into the 5th Avenue, which they pursue until they reach a convenient point for diverging to the densely populated parts of the city.
This Reservoir is 420 feet square on the top, measuring on the cornice of the main wall; it is 425 feet square at the top of the cornice of the pilasters, and 436 feet square at the base, measuring from outside to outside of the corner pilasters, covering a little over four acres. The height of the walls is 45 feet above the streets around, and about 50 feet above the foundations.
The water is 36 feet deep when it reaches the level designed for its surface (which is 4 feet below the top of the walls) and the surplus, when the Reservoir is full, passes into a well in the division wall and is conducted by a sewer in 42nd street to the Hudson River, which is one mile distant.
The Reservoir is calculated to hold 20,000,000 gallons.
The outside walls are constructed with openings in them so that by entering the door on 42nd street one may walk entirely around the Reservoir within the walls. One object of this arrangement is to obtain the greatest breadth with a given quantity of material; another is to afford an opportunity to examine the work so as to guard against leakage; and another, to prevent any moisture finding its way through to the exterior so as to cause injury to the wall by the action of frost. This kind of open work of the wall rises to within about 8 feet of top water line. Inside of these walls an embankment of puddled earth is formed with suitable breadth of base to give security to the work, and the face of this earth next to the water is covered with a wall of hydraulic masonry 1¼ foot thick. The top of the embankment is covered with stone flagging, forming a walk around the top of the Reservoir. The bottom of the Reservoir has a covering of concrete 1 foot thick; thus when it is empty there will be seen two basins having the sides and bottom formed of masonry.
A section of the wall of one side of the Reservoir, including the embankment, is 17 feet wide at the top, 35 feet wide 16 feet below the top, and 76 feet wide at the bottom: the cornice projects on the outside and the coping on the inside so as to make the width of the top 21 feet. An iron railing bounds the outside and inside of the walk around the top.
The outside of the Reservoir is built on a slope of one sixth its height, or two inches to the foot, and an Egyptian cornice projects at the top of the main walls and the pilasters.
At the entrance on the 5th Avenue a stairway leads up to the top of the Reservoir.
Terraces are built around at the foot of the walls and covered with grass, giving a rich finish to the work.
This Reservoir may be considered the termination of the Croton Aqueduct, and is distant from the Fountain Reservoir on the Croton, forty and a half miles.
The whole cost of the work, exclusive of the pipes in the city below the Distributing Reservoir, is about 9,000,000 dollars. Adding to this the cost of pipes and arrangements for distributing the water in the city, will make the total cost of supplying the city of New-York with water about 12,000,000 dollars.[7]
The water was introduced into the Distributing Reservoir on the 4th of July, 1842, and the event was hailed by the citizens of New-York with an interest scarcely less than that pervading the whole American people at the remembrance of the event, the anniversary of which, was on that day celebrated.
At an hour when the firing of guns and the ringing of bells had aroused but few from their slumbers, and ere the rays of the morning sun had gilded the city domes, the waters of the Croton gushed up into the Reservoir and wandered about its bottom as if to examine the magnificent structure; or to find a resting place in the temple towards which they had made a pilgrimage.
The national flag floated out from each corner of the Reservoir, and during the day thousands of the citizens visited it giving demonstrations of joy and satisfaction at the accomplishment of this great work.
The 14th of October following was set apart as a day for the celebration of the introduction of the water into the city: and it was an occasion of unrestrained enthusiasm and joy. Multitudes came in from the country around, and from sister cities:—all business was laid aside for the pleasing ceremonies of the day, and the Croton water, with the beauty and grandeur of its fountains, met with a welcome which showed that its value was appreciated.
The advantages, the comforts and blessings of this supply of pure water will be appreciated as the city extends the means for its use, and the time is not distant when she will regard it as a treasure which was cheaply purchased, and will proudly point to the noble work which she has achieved not only as an example of her munificence, but as an illustration of what art and science can accomplish.
With cleanly streets, and the public parks beautified with the fountains which send forth cooling and refreshing vapours upon the air, the citizens will forget to leave the city during the warm months of summer, and the sea-shore, the mountain-tops, and watering-places, will fancy their beauty has faded, since they cease to be visited.
The foreigner who visits this country will find the Croton Aqueduct an interesting specimen of our public works, and will be pleased with a pedestrian tour along the line of work to the Fountain Reservoir among the hills of the Croton. Besides becoming acquainted with the important features of the work, he may enjoy much that is beautiful in American scenery. In his course along the Aqueduct he may see the majestic palisades which for a distance wall the right bank of the Hudson; he may view the Tappan and Haverstraw bays with their ever-varying scenery, and the dark gorge where the Hudson emerges from the Highlands with its white bosom.
Along the Aqueduct there are also many picturesque scenes where the mountain stream leaps among the rocks in the deep ravine which guides its course to the Hudson.
The country is interesting also from the associations with which it has been invested by the pen of our novelists. The region of the Croton where the Fountain Reservoir is formed, is a part of the district where the scene of the “Tale of the Neutral Ground” is laid; and one may fancy there the figure of Harvey Birch, beneath his pondrous pack, casting a shadow at night along the moon-lit slopes.
Leaving the valley of the Croton we come out upon the Hudson at the head of the “great waters of the Tappan Zee,” beyond which the early inhabitants of New-Amsterdam dared not to voyage without first “settling their family affairs, and making their wills.”
As we approach Tarrytown we find the localities which were pictured in the “Legend of Sleepy Hollow,” and easily recognize the Old Dutch Church near which the affrighted Ichabod Crane was so sadly unhorsed by the headless Hessian. We find in this vicinity also, the place noted as the “spot where the unfortunate ‘Andre’ was captured.”
Besides the romantic and diversified scenery of the Hudson which is in view from the line of Aqueduct, the visitor may find highly cultivated grounds and delightful country seats, and among them that of our distinguished countryman, Washington Irving, where he sought a rural retirement for his literary pursuits. But it is unnecessary to speak further of the objects which are calculated to interest the visitor to this part of the country: we would only invite the stranger who visits the city of New-York to go forth and visit her noble Aqueduct: when he has become acquainted with the magnitude and grandeur of its construction, then he may turn aside for prospects to admire and incidents to interest.