> Hi Steve.
> I see what youre saying about a very shallow lake
> of water used as a leveling device, say only an
> inch deep or so .
> In fact the entire course surface wouln't need to
> be covered in water.
> Islands would form in the high spots which would
> remain dry allowing them to be worked upon, the
> work eventually reducing the dry islands down to
> the shallow water level.
> A quantity of water could then be released further
> exposing the 'high spot' islands which are again
> dry worked down. The process is repeated over and
> over until eventually there are no large islands
> and of course no water. In other words a flatish
> surface consisting of numerous very small dry
> islands and small very shallow pools.
> Imagine a parking lot after rainfall, small, very
> shallow puddles all over the place. Good
> Anyway this would negate the problem of working in
> dirty opaque water, and would ensure minimum
> material removal and therefore effort in order to
> achieve acceptable flatness. No measuring
> equipment or projection equipment required.
> Obviously this would only work on a horizontal
> reasonably flat surface.
> Actually I'm surprised that Lehner even considered
> level reduction work going on underwater.
I don't think Lehner was talking about working underwater. I think he was referring to all the chiseled dust shooting off the dry regions and entering the wet regions, making them murky and muddy, not to mention adding mass that could play havoc on the water level. Of course, a few young workers studded across the work surface could monitor the water level and flag when the water rises above nominal level when too much rubble gets thrown into it, or reduces below nominal if evaporation is in excess. But for such a shallow pool I'm not sure how problematic evaporation might be. I also can't fathom how the wet, muddy rubble would be cleaned off periodically from a large roughshod work surface.
It would be very interesting to attempt to level a bedrock plane on a test area using this method. I've never seen it used.
How can any of us ever know, when all we can do is think?
Edited 1 time(s). Last edit at 15-Jan-17 03:33 by Origyptian.