For pumping a well a valved working-barrel with valved sucker is attached to the lower end of the tubing, a perforated " anchor " being placed below.
The tidal action of the gulf is so slight and the marshes are so low that perfect drainage cannot be obtained through tide gates, which must therefore be supplemented by pumping machinery when rains are heavy or landward winds long prevail.
Owing to the pumping of the brine for the salt-works there is a continual subsidence of the ground, detrimental to the buildings, and new houses are mostly built in the suburbs.
Their movement in an upward or downward direction in Limulus and Mygale must exert a pumping action on the blood contained in the dorsal arteries and the ventral veins respectively.
A mine should always be opened by drift or entry if practicable, as thereby the expense of hoisting and pumping is avoided.