Illustration: Mode of Suspending theTubbing to the Rods.
The cement is inserted behind thetubbing by close ladles, Figs.
The ring holding the moss box is hung from the bottom joint in the tubbing by sliding rods.
The introduction of cement behind the tubbing to complete its solidity.
This process is more expeditious where there are small quantities of water; but where the water is excessive greater delay is caused by contending with it than from putting in numerous sets of tubbing to stop the feeders separately.
The tubbing is suspended in the pit by means of six rods, which are let down by capstans placed at a distance of 30 feet above the top of the pit.
The bottom ring of tubbing and the ring carrying the moss box have their top flange turned inwards, but their bottom flange outwards.
When the tubbing nearly reaches this crib, the rock is removed piece by piece, and the top ring of tubbing is placed close up against the crib.
On the base so prepared, four or more rings of tubbing in segments are fixed, the top ring coming close against the bottom of the moss box.
The tubbing used in England has almost invariably been of cast-iron; on the Continent, till recently, tubbing of wood has chiefly been used.
Under these conditions the next process is;--The introduction of cement behind the tubbingto complete its solidity.
The connection between each ring of tubbing is so carefully made, that the repeated wedging of the joints, as in the ordinary system, is rendered unnecessary.
To give the crib a firm and secure position, it is tightly wedged with wood, both behind and between the joints; the tubbing is then built upon it to the next wedging crib, which rests upon a bell-shaped section of rock.
This kind of tubbing can be carried to any height, till the water finds an outlet at the surface, or till strata containing water can be tubbed off, as by the modes of tubbing already described.
Indeed, when a water-run requires to be stopped by tubbing or cribbing, the circular is the only shape which presents a uniform resistance in every point to the equable circumambient pressure.
Later on, these collars were replaced with iron bars that held the wood against which the jacks bore in order to press the tubbing downward (Pl.
This tubbing was perfectly tight, all the surfaces of the joints having been made even and provided with strips of lead one-tenth of an inch thick.
The great difficulty was to cause the tubbing to descend vertically, and also to overcome the enormous lateral pressure exerted upon it by the earth that was being traversed.
The exterior of this was provided with 12 oak guides, which sliding over the surface of the tubbing had the effect of causing the tube to descend vertically.
The sands and gravels were passed by means of a single section of tubbing 31 feet in length, which was not stopped until it had penetrated a stratum of white chalk to a depth of two yards.
This caused the tubbing to descend about eight inches more, when it came to a standstill.
All this, however, is a digression from the freshman whom we have seen safely through his tubbing troubles, and have selected for a Lent Boat.
With these ideas he becomes as a freshman a member of his college boat club, and adds his name to the "tubbing list.
The dressing-room of the barge is sacred to the members of the eight, who at the present season are engaged in tubbing the freshmen in the hope of finding a new oar or two.
During the Morrison wine which ended the season of tubbing on the river, the captain of the Balliol fifteen threw his arms about me, and besought me to play on the team.
The crowning event of the season of tubbing is a wine, to which are invited all boating-men in college, and the representative athletes in other sports.
After a fortnight's tubbing in pair-oars, the better candidates are tubbed daily in fours, and the autumn races are on the horizon.
The interval between the back of the tubbing and the sides of the borehole is then filled up with concrete, which on setting fixes the tubbing firmly in position.
With increase in depth, however, the thickness and weight of the cast iron tubbing in a large shaft become almost unmanageable; in one instance, at a depth of 1215 ft.
Upon this the tubbing is built up in segments, of which usually from 10 to 12 are required for the entire circumference, the edges being made perfectly true.
The whole weight of the tubbing is made to bear on the moss, which squeezes outwards, forming a completely water-tight joint.
Piran a visit; after they had prayed together, "It is mytubbing time," said Piran.
Tubbing is now adopted in many cases as a substitute for brick-walling.
The tubbing consists of short portions of cast-iron cylinder fixed in segments.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "tubbing" in a variety of sentences. We hope that you will now be able to make sentences using this word.
