George Daniels was quite an admirer of Frodsham watches.
In his book with Cecil Clutton he writes:
"The numerous members of the Frodsham family were in business from some time before 1780. William Frodsham, the second generation of watchmakers, married Alice, a grand-daughter of John Harrison. Charles, the last member of the family to be active in watchmaking, died in 1871, but the firm still continues.
From some time before the middle of the last century (1) they began making lever escapements and chronometer escapement (2) watches of the very highest quality, and continued to do so until the outbreak of the war in 1939. For the 1851 Exhibition they introduced the 3/4 plate calibre which they marked AD.FMSZ, which continued subsequently to be put on all their highest grade work. The significance of FMSZ is said to be found by putting the name Frodsham against the numbers thus