How did the “workers carry glass pane across street, someone smashes through it” thing seen in movies come about?

Question

How did the “workers carry glass pane across street, someone smashes through it” thing seen in movies come about?

In: Other

Answer 1

In early silent movies the picture quality was relatively poor and large panes of glass were expensive, so large panes of glass were handled with extreme care. This meant though you could set up a film scene with people appearing to carry a pane of glass and the audience believe it even if the glass wasn’t there, so you could create a running gag with someone appearing to step between two people carrying a pane of glass and maintain the gag until in the final scene someone actually step through a real pane of glass.