In 1862 the first issue
of Trysorfa'r plant (The Children's treasury) appeared, edited by Thomas
Levi on behalf of the union of Calvinistic Methodists.
Its circulation was considerable among readers of all
denominations. Each issue
contained a variety of material in clear, simple language. By 1881
Trysorfa'r plant sold 40,000 copies a month and over one and a half
million copies were sold between 1862 and 1911.