Cuyler Page wrote:
> Your measuring story reminds me of a carpenter I once worked with
Cuyler,

Your tape measure example is one reason I prefer working with folding or 
straight bar rules. But that is not always convenient. My grandfather 
taught me how and when to measure an inch in from the end of the tape. I 
also tend to have multiple measure tools on the project. I have not 
counted how many on this one. And we read measure off to each other in 
Imperial or Metric depending on how accurate we want to be (the metric 
for higher accuracy)... we are roughly running 4' x 6' and smaller 
SALVAGED slabs with a 1/8" - 1/4" joint (allowing an angle in the 
joints) -- there is an intended aesthetic to the variation in tolerance. 
As we measure terra cotta for the Brits as a team we are used to 
dual-measure as we give them everything in metric, but we check all 
measure in Imperial as the original terra cotta was not made in metric. 
We also tend to measure 6-7 times and once we think we have it right one 
of us checks again. There is no more stone than what we have to work 
with. We are also dealing with level and square. My tolerance criteria 
is, "If they pee on the floor we want it to stay there." So we need to 
think in intuitive terms of the viscosity of urine, flow rate, and the 
attraction it has to unsealed marble. I figure there is more wiggle room 
in that than we need. We are also at times putting in pieces in a 
sequence that is near to as backwards as one can get... as the pieces 
that should probably go in at the same time are across the street, 4 
flights down, 4 flights up and a few hours of preparation work away 
(having to literally grind the wall off the backsides of the stones). It 
took us a few hours to figure out our levels... the $100 DeWalt laser 
level, about the size of a torpedo level, turned out to be worth crap by 
the way... I also brought in a length of plastic tube with water in it 
but that confused everyone as they had never played with such a device. 
The transactional cost of the communication exceeded the benefit of the 
result -- when one lifted on one end of the tube the guy on the other 
end lifted his end as well. The whole issue of spontaneous artesian 
wells came to mind. Let alone other ideas. Our squares seem to keep 
diminishing in number, I bought 2 more last night just in case. Our most 
critical problem though is the assumption that the original floor, 
itself made up of salvaged material, was square to begin with. What we 
are finding out is that we cannot find any square corners, but the space 
we are working in is fairly square. Metal studs, we were thrown off that 
the screw head takes up 1/8" and we lost 1/4" in the enclosure of two 
walls as a result. On sheetrock the board compresses to envelope the 
screw head, the cement board does not. We also have to deal with the 
work vision in that we are used to working to make it 'look right' on 
existing structures and we do not particularly think in terms of new 
work that anything would ever be square or precise in measure. Even 
though it makes sense to think in terms of precise measure the problem 
is that without extensive pre-survey work it is difficult to keep the 
compounded complexity of a skewed 3-D masonry object in one's head, or 
in other words to grok it right off. So here we are sorting out between 
us both directions of perception.

][<en

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