When I generate a Transform Column by sending Transform Column to a data table, I get the a reference to the Column as a return value.
When I generate a Transform Column by sending Transform Column to a GraphBuilder Object, I get a refernce to a Graph Builder as a return value - no reference to the column 
So asking this col2 for it's name doesn't work.
Interestingly, using col2 as an argument when talking to the GraphBuilder - WORKS.
Where can I find more information about referencing transform columns?
Names Default to Here(1);
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );
gb = dt << Graph Builder();
col1 = dt << Transform Column ("col1", Formula(1/:height));
col2 = gb << Transform Column ("col2", Formula(1/:height));
Show(Name Expr(col1));
Show(Name Expr(col2));
gb << Variables(X(:height), Y (col1));
gb << Variables(X(:height), Y (col2)); // gb seems to know col2
Show(col1 << get name());
Show(col2 << get name());
Show(Column(dt, "col1"));
Try(Show(Column(dt, "col2")), "dt doesn't know the column");
