set table column width

How can I set the width of a column in my table?

I can read the width like so…
set w to width of table column 1 of theObject

but I can’t set it with this…
set width of table column 1 of theObject to 300

(note: width is a real number according to the AS Terminology Reference but 300.0 doesn’t work either or (300 as real) etc.)

I found my problem. After I explicitly defined my table I was able to set the column width. Here’s the code that works for future reference.

set theTable to table view 1 of scroll view 1 of window 1
set width of table column 1 of theTable to 300