U.S. Patent No. 490,964 (.pdf)
Designed for the distinguished businessman who likes his alcohol (and which ones don't?), a combination clothes brush, flask and drinking cup is described herein. Reading into the description a bit indicates that the desire was to make the flask slim enough that the block on the brush isn't oversized, which, in other words, means that you can't tell there's a flask on the brush. You can, therefore, freely sip your alcohol below the radar of, perhaps, your superiors. No wonder it's tradition nowadays for suits to go to work tipsy. At least their jackets look professional!