Sentence:  N.B.—Mr Broughton proposes, with proper assistance, to open an academy at his house in the Haymarket, for the instruction of those who are willing to be initiated in the mystery of boxing: ... <WSD>muffles</WSD> are provided, that will effectually secure them from the inconveniency of black eyes, broken jaws, and bloody noses. 
Meaning of the word marked with <WSD> tags:  A boxing glove.