A window with one or two sashes (sections) which can be slid vertically to make an opening. Cylindrical cast iron weights are invisibly installed in the window casing to counter balance the weight of the sash so that it doesn’t drop after opening.
Related post which may be on interest
About The Author
I am a beekeeper and an allotment grower and this site features articles on those subjects including recipes made from the produce from my allotment and from my bee hives. I have an interest in a great many things (too many actually) and some of those experiences, and the joy and learning I acquire from them, may also randomly appear here.