Victorian illustration to download showing two boys operating an envelope making machine, on display at the Great Exhibition of 1851. One boy inserts a lozenge-shaped sheet of paper into the machine, which is driven by belts, wheels and cams powered by steam, at the rate of 60 sheets a minute. It folds four flaps to form the envelope, and applies gum to the appropriate flaps. The other boy will take the finished envelopes to be packed. This machine was developed by Messrs Delarue (De La Rue), printers, stationers and manufacturers of playing cards – later in the Victorian era they printed postage stamps and banknotes. In their factory 11 of these machines produced 396,000 envelopes a day.