Mark V Shuttering.
The angle-iron stay with cross-brace raised, and the blocking-box showing its internal clamping-gear.
[II]
The chief desiderata in designing a satisfactory Pisé plant appear to be these:
All constituent parts should be reasonably light and easy to handle. The shutters should be rigid and not liable to warp, without being expensively constructed. The shutters, when clamped in position, should be firmly and positively supported, without deviation from the vertical.
The fairway between the shutters must be as little obstructed by the cross-braces as may be, leaving good room for the men on the wall to tread and ram.
The through-pins by which the shuttering rests upon the base wall or on a completed course of Pisé, must be easily withdrawn without injury to the wall.
The shuttering must be easily disengaged and removed from the wall, one side at a time.
The special corner-piece must have some means of rigid attachment to the ordinary shutters on the two meeting walls.
There must be some means of blocking off the shuttering at any desired point, for the forming of door or window openings at any level.
The whole apparatus must be as simple and as fool-proof as possible, and built to stand rough usage and exposure to the weather.