[betty boop]

A great read you might enjoy....

[MHGinTN]

Thank you, bb, I will read through it at my next break. [I still contend the big blocks were poured in place, then later internal solid blocks were placed. and more external blocks were poured in place, then solid internal blocks were placed, then more poured in place, etc, etc. 'Etc' the escape for the non-scientist, don'tcha know!]