University of Roorkee, Roorkee.
*The first article of this scries appeared in the Journal of the Institution of Engineer (Iniha) Vol. 32 No. 2. The next series II, III and IV have appeared the “IRRIGATION AND POWER” in Vol. IX, No. 1, January 1952; Vol. IX, No. 4, Oct. 1052: and Vol. XIV. No. 2. April 1957 respectively The present one is the fifth & final paper in the series.
The 5th and the final paper of the series (design of tubewells for irrigation) discusses the implications of d, the depression or draw-down in the design of tubewell. The choice of d naturally leads to the selection of pumping plant, which has been discussed in the paper. An empirical formula for calculating the capacity of a compressor for an air lift pump as developed by the authar has been given. A new type of pumping arrangement called the propeller cum bore-hole pump has been described. This arrangement is particularly useful for pumping out water from great depths through small bares in which it is impossible to lower an ordinary bore-hole or submersible pump. Such a case often presents itself in old tubewells where the spring level has either dropped or the depression has increased due to aging. So far in such eases, the drop in discharge could not be improved.
