Anyhow, the Civil War-era Ketchum hand grenades somewhat resemble yard darts. They were made in three sizes: one, three and five pounds. The Union purchased more than 92,000. The egg-shaped cast iron bodies were charged with powder. The tapered wood with three fins attached was inserted in the rear of the body to hold the powder in place. Then a primer was inserted into the nose followed by a plunger with a two-inch wide head. This picture shows the one-pound version.
The grenades were patented during the summer of 1861 by William F. Ketchum of Buffalo, NY. He was primarily known for his farm implement innovations. He was the first to offer a practical hay mowing machine, which hit the market in the mid 1840s.
Ketchum grenades were used during assaults on Confederate earthworks at Port Hudson, Louisana, in 1863. The defenders spread out blankets to catch the grenades so they wouldn't detonate. Then the Confederates would fling them back down into the attackers.
The grenades often failed to explode. Maybe plain yard darts would have worked better.