What is the purpose of the milled slot in Frank Lloyd Wright’s windows?

Why is there an invisible slot milled in Frank Lloyd Wright's windows? Should we fill it with something, and if so, what? Architects, homeowners, historians and restorers are welcomed to weigh in.

A blocked sight-line to be restored to Wright’s plan

You don't see many pictures of the kitchen in our gallery because we've not yet solved an aesthetically-complex issue: a sight-line destroyed by a modern appliance. We have a fix.

Tracking the restoration and preservation of a 103-year-old Frank Lloyd Wright house

The restoration and preservation of Frank Lloyd Wright's Elizabeth Murphy House.