Page QR CODE 08/24Industrialisation 1920

From the 1920s onwards, the telephone was increasingly successful—thanks in particular to government investment. The telephone would also become a consumer good and be manufactured on an industrial scale.
Wooden components would be replaced for metal parts.
Many column telephones were made by such companies as Grammont, Picart-Lebas, Burgunder, and AOIP. 
Sometimes the wooden models would be converted into a metal version of the same model, as was the case for Grammont and Picart-Lebas telephones.

On the top shelf, from left to right, are a Thomson Houston column phone, a Vandenboes column phone, and a Grammont phone.

On the middle shelf are a Thomson Houston low model with an elaborate bracket, a Picart-Lebas column on a rectangular base, and on the right, a column telephone with an arched suspension hook.

At the bottom left is a Western Electric model (which was very common in the United States and England); at the bottom right is an Ericsson telephone; and in front of it is a Thomson Houston column telephone.