Image: Wilson's Creek National Battlefield; WICR 30377
That, Neatoramanauts, is a hand grenade patented in 1861 by William F. Ketchum. If someone threw one at you and you ketchum, you'd be in trouble. Unless you have a blanket.
Why? Read on.
From Trans-Mississippi Theater Virtual Museum:
The Ketchum grenade was a hand thrown weapon with limited range used primarily during sieges; the fins stabilized the grenade’s flight and assured it landed nose first, which was required for detonation; this requirement also made them largely inefficient. They were manufactured in one, three, and five pound sizes.
Union forces who used the Ketchum grenade in great numbers in their attacks at Port Hudson found its limitations. Many failed to explode when thrown into the Confederate defenses, and were subsequently thrown back into Union positions. The Confederates also devised a method to render the Ketchum useless by rigging blankets to catch the grenades.
Link - via The Civil War Parlor