Plate 23



   It is important that the earth be placed and rammed under the pipe of the lockpipe, as satisfactory natural settlement will not take place below the pipe.

   Upper left: The second row of ramming from an oblique angle, so that the earth is forced under the lockpipe. From now on very little hand work and only carefully supervised bulldozer operation is necessary.

   Upper right: Water from rain (during the construction of a medium-sized farm dam) drains out through the lockpipe. The oil drum and posts are placed at the two open ends of the lockpipe to prevent it from being covered and lost during the construction of the dam.

   Lower left: The volume-cone strainer in position on the inside of a newly completed dam.

   Lower middle: The lockpipe valve with eight-inch lockpipes.

   Lower right: The large volume of water from the opening up of an eight-inch lockpipe valve.

   The lockpipe system is our own. The system, together with many items of the equipment, are protected by various patents and registered designs (see Chapter XIII).