Air-gun

The famous air-gun of Von Herder will embellish the Scotland Yard Museum.
“An admirable and unique weapon,” said he, “noiseless and of tremendous power: I knew Von Herder, the blind German mechanic, who constructed it to the order of the late Professor Moriarty. For years I have been aware of its existence, though I have never before had the opportunity of handling it. I commend it very specially to your attention, Lestrade, and also the bullets which fit it.”