Volley gun
Two notable artillery-sized volley guns were developed in the mid-19th century, although neither was particularly successful in practice. Developed in the 1860s and based on an 1850s design by a captain Fafschamps, the French mitrailleuse is an example of a multi-barreled volley gun that could fire all of its barrels simultaneously or sequentially over a short period of time. Also developed in the 1860s, General Origen Vandenburgh of the New York State Militia designed a weapon that had eighty five parallel .50 caliber rifle barrels. After failing to sell the weapon to the United Kingdom, he reportedly sold a small number to the Confederate States of America, although there is no record that they were actually used. One Vandenburgh gun was located at Fort Fisher, North Carolina, and another reportedly at Salisbury, NC.
Mitrailleuse
The first "mitrailleuse" was a manually fired 50-barrel volley gun originally developed in Belgium in 1851 by the Belgian Army Captain Fafschamps, who made a rough prototype and drawings of his invention. The system was improved during the 1850s by Louis Christophe and the Belgian engineer Joseph Montigny, with the completion of the 37-barrel Montigny mitrailleuse in 1863. From 1859, Joseph Montigny proposed his design to Napoleon III, which led to the development of the French Reffye mitrailleuse, designed by Jean-Baptiste Verchère de Reffye with the collaboration of Montigny, and which was adopted by the French Army in 1865. Initially kept under wraps as a secret weapon, it was widely used in battle by French artillery during the Franco-Prussian War (1870–71). Smaller numbers of other designs, including the Gatling gun, were also purchased by the French government during the latter part of that conflict. The Reffye model had initially been built in small numbers and in secrecy: only about 200 were available at the beginning of the conflict. This also kept regular French field artillery in a neglected position in the eyes of French emperor Napoleon III, with dire consequences during the Franco-Prussian War of 1870–71.