Round, gray-colored, lead bomb casing. There is a hole in both the top and bottom halves where a bolt wrapped in or containing dynamite would be inserted. There is a smaller hole in the top half of the casing where the fuse for the bomb would protrude. The casing weighs approximately 3-4 pounds and is approximately the size of a baseball.

This bomb was introduced as evidence in the Haymarket Riot trial, where the prosecution alleged it was made by Louis Lingg. A bomb of this type was thrown at the Haymarket Square meeting on May 4, 1886. This bomb casing was given to Juror J. H. Brayton by Captain Michael Schaack in December 1887. The cover letter that accompanied the casing can be seen in the Additional Manuscripts section of the Haymarket Affair Digital Collection.

Donated to the Chicago Historical Society by Robert Brayton (CHS 1979.154ab).