The caliche is worked up in loco for crude nitrate by extracting the salts with hot water, allowing the suspended earth to settle, and then transferring the clarified liquor, first to a cistern where it deposits part of its sodium chloride at a high temperature, and then to another where, on cooling, it yields a crop of crystals of purified nitrate.
At one end of the chief square of the town, the Piazza Maggiore, is the cistern by which the town is supplied with water, and a large fountain.
In dip workings the tail rope is often made to work a pump connected with the bottom pulley, which forces the water back to the cistern of the main pumping engine in the pit.
Caiatia has remains of Cyclopean walls, and under the Piazza del Mercato is a large Roman cistern,which still provides a good water supply.
There are remains of baths and a cistern of Roman date.
Within the circuit which they enclose, now under cultivation, are two summits, one occupied by a Roman amphitheatre [the other by a tower (?)(?) of uncertain date]: a Roman cistern also is visible.
Above sea-level; here is a cistern, divided into ten large chambers, in brick-faced concrete.
- Wastage of water in the boilers should be made good automatically from a cistern controlled by means of a ball-cock.
The tanks are commonly constructed of wood lined with lead, or tarred inside, and are placed in terrace fashion each a little higher than the next in series, to facilitate the flow of solution through them all from a cistern at one end to a well at the other.
The district council are also empowered to obtain an order of justices directing the closing of any well, tank or cistern, public or private, or any public pump the water from which is likely to be used for drinking or domestic purposes, or for manufacturing drinks for the use of man, if such water is found to be so polluted as to be injurious to health.
If, on the other hand, water is suddenly drawn off from a cistern supplied through a ball-cock, the flow through the ball-cock will be recorded, and will be represented by a sudden rise to a maximum, followed by a gradual decrease as the ball rises and the cistern fills; the result being a curve having its asymptote in the original horizontal line.
The cistern of Arcadius, to the rear of the mosque of Sultan Selim (having, it has been estimated, a capacity of 6,571,720 cubic ft.
Of water), the cistern of Aspar, a short distance to the east of the gate of Adrianople, and the cistern of Mokius, on the 7th hill, are specimens of the open reservoirs within the city walls.
The cistern of Bin Bir Derek (cistern of Illus) with its 22 4 columns, each built up with three shafts, and the cistern Yeri Batan Serai (Cisterna Basilica) with its 420 columns show what covered cisterns were, on a grand scale.
The supply from the cold water cistern enters the bottom of the cylinder, and thence travels by way of the return pipe to the boiler, where it is heated, and back through the flow pipe to the cylinder, which is thus soon filled with hot water.
The following identifications have been suggested: Birket Isra`il, near St Stephen's gate; a large cistern, near St Anne's church; the "Twin Pools," north of the Haram (the ancient Temple area); the Hammam esh-Shifa', or pool of healing, west of the Haram; the Virgin's fountain, south of the Haram; and the "Pool of Siloam."
The site is one of great strength, and is now occupied by a fort, in the construction of which traces of the outer walls and of huts, and several wells and a cistern, all belonging to the primitive village, were discovered, and also the remains of a villa of the end of the Republic.
The whole operation of thus changing a filter occupies about ten minutes, and there is no need for anyone to enter the hot cistern to detach the bags, which are removed in the open air above the mud tank.
Another method of enabling more work to be done in a given time in a given cistern is the use of a bag twice the ordinary length, open at both ends.
Each cistern is fitted kith a perforated false bottom, on which a blanket or specially woven cloth is placed, to receive the char which is poured in from the top, and packed as evenly as possible until the cistern is filled.
The cistern being thus packed and settled is closed, and the syrup from the bag filters, heated up to nearly boiling point, is admitted at the top until the cistern is quite full.
A small pipe entering below the false bottom allows the air in the cistern to escape as it is displaced by the water or syrup. In some refineries this pipe, which is carried up to a higher level than the top of the cistern, is fitted with a whistle which sounds as long as the air escapes.
A cistern well packed with 20 tons of char will hold, in addition, about io tons of syrup, and after settling, this can be pressed out by allowing second quality syrup, also heated to nearly boiling point, to enter the cistern slowly from the top, or it may be pressed out by boiling water.
By carefully watching the flow from the discharge cock of the cistern the change from the first liquor to the next is easily detected, and the discharge is diverted from the canal for the first liquor to the canal for the second liquor, and, when required, to the canals for the third and fourth liquors.
After the sweets have come away, cold water is passed through the char until no trace of lime or sulphate of lime is found in it; then a large manhole at the bottom of the cistern is opened, and the washed and spent char is removed.
In former days, when refining sugar or " sugar baking " was supposed to be a mystery only understood by a few of the initiated, there was a place in the refinery called the " secret room," and this name is still used in some refineries, where, however, it applies not to any room, but to a small copper cistern, constructed with five or six or more divisions or small canals, into which all the charcoal cisterns discharge their liquors by pipes led up from them to the top of the cistern.
Each pipe is fitted with a cock and swivel, in such a manner that the liquor from the cistern can be turned into the proper division according to its quality.
P. di Cesnola, Cyprus, 1878 passim) and to the British Museum (Excavations in Cyprus, 18 94 (1899) passim); but the city has vanished, except fragments of wall and of a great stone cistern on the acropolis.
The mosque to which the tower belongs is a large brick building erected by `Abd el Mumin; the interior is adorned with marble pillars, and the whole of the crypt is occupied by a vast cistern excavated by Yakub el Mansur.
P. 362) gives the following note from his laboratory book on the 10th of September 1822: "Polarized a ray of lamplight by reflection, and endeavoured to ascertain whether any depolarizing action (was) exerted on it by water placed between the poles of a voltaic battery in a glass cistern; one Wollaston's trough used; the fluids decomposed were pure water, weak solution of sulphate of soda, and strong sulphuric acid; none of them had any effect on the polarized light, either when out of or in the voltaic circuit, so that no particular arrangement of particles could be ascertained in this way."
P pe to water house cistern FIG.
At this point in the Haram enclosure there is an enormous underground cistern, known as the Great Sea, and this may possibly have been the source of water supply for the Greek garrison.
A little to the south-west of the point where the road turns towards the Propylaea was found a large rock-cut cistern or reservoir which Dorpfeld identifies with the Enneacrunus.
Large doors at the side of the cistern are then opened, and as soon as the bags are cool enough they are removed at the expense of very exacting labour and considerable time, and fresh bags and sheaths are fixed in their places ready for filtering fresh liquor.
By this arrangement the work of a refinery can be carried on with about one-half the cisterns otherwise required, because, although it does not reduce the number of bags required per day for a given amount of work, it enables the refiner to use one cistern twice a day with fresh bags, instead of only once as heretofore.
When the sound ceases the cistern is known to be full, and the entrance of further water or syrup is stopped.
A very usual size of cistern forming a convenient unit is one that will hold 20 tons of char.
The syrup in the cistern is allowed to remain for about twelve hours, by which time the char will have absorbed all the colouring matter in it, as well as the lime.
The buildings may be divided into five groups: (I) a large cistern in five compartments, each measuring 39 by 17 ft.; (2) habitations both for the owners and for slaves, and store-rooms; (3) baths; (4) habitations for slaves; (5) belvedere.
Others would read:" remember thy cistern "(Bickell), or" thy well "(Haupt), that is, thy wife.
Just then the nurse came into the cistern-house bringing her little sister.
Here a series of excavations, carried out by the British School in 1896-1897 under the direction of Cecil Smith, revealed the foundations of an extensive Greek building, the outlines of which correspond with those of a gymnasium; it possessed a large bath or cistern, and was flanked on two sides by water-courses.
Pipes should also be laid having a connexion with all the various greenhouses and forcing-houses, each of which should be provided with a cistern for aerating the daily supplies.
Every installation is made up of a boiler or other water heater, a tank or cylinder to contain the water when heated, and a cistern of cold water, the supply from which to the system is regulated automatically by a ball valve.