Hello Michelle,
In the mentioned book, there's a vase, same model but slightly smaller @ 8", with a marine/riverboats image, called "Cérès". The guirlande or frieze around the rim is the same.
It is mentioned, literally translated, that this type of enamel was in production up to 1924, but the 'golden age' lays between 1880-1910.
The style changed with time, due to trends and fashion but also due to commercial strategies.
Usually there are 4 panelled images on a white opaline background, surrounded by floral ornaments. Pieces of exceptional quality were signed 'L et Cie-St Denis-Paris'.
The series 'Delft' is strongly linked to this type of décor. On a white opaline background, a blue, monochrome décor has been applied with Dutch scenes, either boats leaving a harbour or landscapes with windmills.
Distributed at, for instance Le Grand Dépôt, it was announced in their catalogue that no other production had given such a beautiful effect for the price that these items were sold for, so basically customers got quality for their money, at a reasonable price.
On the decorating process it is mentioned that they used a few background colours, opaque or not, and a design was transfer printed with ink. Next the enamel was applied in powder and passed under a 'mitten' to melt the powder.
I hope this answers your question ....