Address: probably an obscure address off PallMall?
The Junior Ganymede is a club whose members are exclusively men of the upper reaches of service, which is to say Servants along the lines of butlers, valets, and gentlemen's personal gentlemen. It serves not only a social function but also an important professional one, in that its members can learn a great deal about prospective employers, as well as about households their employers may visit.
As a result, an important bylaw of the club requires that every member write an account of his employer(s) in a large tome containing all such information. We are reliably informed that this "volume" is more properly a series of journals, composed more or less chronologically, with an index volume updated continually by each writer. In addition to the professional assistance thus rendered, these reminiscences afford considerable amusement to their readers. Not surprisingly, the texts are carefully guarded from the prying eyes of non-members; there is reason to think that their publication would not only lead to great embarrassment but also have large political ramifications, including possibly the fall of the government.
During the 1920s, Bertie Wooster's man Jeeves composed an entire volume devoted to nothing but his employer's more amusing and farcical exploits, but these were eventually destroyed by Jeeves himself when the material was stolen from the club library.
P.G. Wodehouse, various short stories and novels about Bertie and Jeeves