Thanks for the detailed and documented response regarding bee escapes.
 
I had not realised that the bees do not like to leave dripping
ladder comb.  Actually one of the advantages I have observed
using this method is that they tend to clean up the mess before
they go - an advantage when producing comb sections.
 
I have tended to leave the escapes on for anywhere from 24 to
48 or more hours to ensure uniform clearing.  The idea of clust
cluster space is new to me too - although it certainly makes
sense when one considers reducing a seven storey hive temporarily
to three or four.  Otherwise who could stack all the supers back
on above an escape board, or shove an escape board in for that matter.
 
I am still looking for optimal measurements for the Quebec style,
seeing as the Porter type do clog, get damaged eaasily in
commercial use, and, I believe, are relatively slow.  The type
using cones may be good, but cost more, and are also subject to
damage in hard use (hired student help).
 
Once again, Thanks