What’s a Wacka?

Caption: “Is that a wacka alert whistle we can hear in the distance?”
In the Language of the Old Guv Printing Office nothing was more important to hear the announcement of a new “Wacka”. Why?
A “wacka” was a juicy rumour so important that an instant crowd of workers would gather on hearing the wacka alert whistle.
Normally they were bullshit and no real good ever came out of spreading a “wacka.”
“Like blowflies gathering around a lump of shit.” That was Kevin “Dago” Stack-Neale’s masterly description of a “wacka crowd” gathering and hovering around eager to hear the latest gossip.
And the English Version goes like this: Whack !-When compositors are gathered together and a tall story is told, or it be doubted that the truth has been told by a speaker, a whack with the composing stick on the frame is given as an indication of unphilosophic doubt.
That is interesting don’t you think?