Why do the window glass of old old building (a) look milky and (b) become thick at the bottom?

Why the window glass of old buildings look milky?

Why is the window glass of the old building thick at the bottom ?

Why the window glass panes of the old buildings are thick at the bottom ?

Why is glass of window panes of very old builidings found to be thicker at the bottom than as the top and why is it milky ?

Rohit went to Jaipur with a school trip to visit some historical places. He and his friends observed that some old glass objects looked milky and windows pane of old buildings were looking slightly thicker at the bottom than at the top. Answer the following questions Under what conditions could quartz be converted into glass?

Rohit went to Jaipur with a school trip to visit some historical places. He and his friends observed that some old glass objects looked milky and windows pane of old buildings were looking slightly thicker at the bottom than at the top. Answer the following questions Is glass crystalline or amorphous?

Give reason for the following. Windows panes of old bulding become thicker at the bottom than at the top.