Page:Professional papers on Indian Engineering (second series).djvu/97

 No. CCXCIII.

DESCRIPTION OF A PLAN FOR FACILITATING THE CONSTRUCTION OF THE STEINING FOR WELLS.

[Vide Plate.]

By W. Bull, Esq., Assoc. Inst. C.E.

By all who have had experience in well building and sinking, it will have been noticed what constant care is necessary to keep the masonry of a well truly cylindrical. This is more difficult as a well gets out of the perpendicular, which at some period happens to nearly every well sunk. This can be almost, if not entirely, obviated, and an absolutely true circle of the same radius be ensured by the use of a cylindrical templet, of a diameter equal to the outer diameter of the well, and inside which the brickwork is to be built. This plan was first designed for, and used in, the construction of Irrigation wells, with a view to facilitating the building simultaneously with the sinking. With dredgers or moats coming out constantly, it is very difficult for a mason to use either tem- plets or straight-edges as applied by hand. With the cylindrical templet neither of the above or any plumbing is required.

In construction the templet will be as shown in the accompanying Plate.

For a larger sized well the parts should be proportionately heavier.

The cylindrical templet can be used in two ways. First-on starting the brickwork of a well it should be placed on the curb, which in nearly all cases is of a slightly greater diameter than the brickwork is intend- ed to be. Four courses can then be built. The templet is then to be raised six inches, and supported in four places by a flattened nail driven 57 I