I have some negatives of photos on glass, when would these have been taken?

Question: I have some negatives of photos on glass, when would these have been taken!?
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Gelatin dry glass plate negatives, as they are officially known, were the first mass-produced, ready-to-use film made available to photographers!. The film, or plates, were made by coating a piece of glass with an emulsion that would remain light sensitive when dry, a great leap forward over previous processes that required the film to be used before the emulsion dried!. For the first time, film could be produced in advance, stored and shipped, greatly freeing up the photographer and increasing the ease with which images could be made!.

Dry glass plates were most commonly used between 1880 and 1920, though for some special applications they remained in use as late as the 1970’s!.Www@QuestionHome@Com

Any time between about the early 1840s and the 1950s,more usually glass negatives were between 1886 and 1940!.Knowing the subject matter would help,are they of people,buildings,landcapes,vehicles!?!? These are clues which would help to narrow down your search!.Www@QuestionHome@Com

daguerreotype photo could be as old as 1837 abe lincoln and edger allen poe had photos taken this wayWww@QuestionHome@Com