In 1747 the French made the important dis covery that, if the earth tamping alMut a shell were omitted. the discharge would ignite the shell fuze. This expedited loading, removed the great danger of shell fire, and increased its use. At this time field carriages were still crude, made of wood. with wooden axletrees. low• limbers, and horses harnessed in tandem. Com mencing about 1765 remarkable improvements were made in ordnance by Gribeanval. ITe had his guns east solid and bored to accurate dimen sions instead of being east to approximate size. This diminished clearance, with the result of no loss of power, in spite of reduced length and weight. Trunnion-rim bases, removable copper vent pieces. and iron axletrees were introduced, and draught lightened by- making the wheels of the limbers higher. An improved vertical 'pin tail' facilitated limbering and unlimbering. Heavy guns had traveling trunnion beds provided on the carriage to distribute their weight over the four whCc1S. The powder cartridge and projectile were fastened together. Aiming was facilitated by the elevating screw and tangent scale, and for moving the piece unlindwred the prolonge and brieoles were used. All parts were made of standard dimensions, so that spare parts could be taken into the field for repair. Car riages for heavy gulls were greatly improved by the use of a pivoted chassis.
llollow projectiles were much used. Grape (a number of shot in a net) were used until su perseded by Grilwarival's canister (a thin can to hold a number of small shot and break up as soon as discharged from the gun). Near the end of the eighteenth century earronades became popular, especially at sea, and were much used. Being short, they were easily loaded, and at the ranges of that day their heavy projectiles with low velocity were very effective.
Early in the nineteenth century Colonel Born ford (r nited States) invented the 'eolumbiad' (q.v. for illustration), a gun of eonsiderable length and having a long chamber, designed to fire at high velocity and low' elevation either shot or shell. This idea was taken up abroad by General Paixhans (q.v.), of France, about 1822, and 'Paixhans guns' came into very extensive use. They were important factors in rendering necessary the adoption of armor for ships. Dur ing the War of 1812 the most important guns in use were the eolumbiads and the carronades of the eighteenth century.
Admiral Dahlgren, United States Navy, in 1856, made the 'Dahlgren guns' for naval use of outline proportioned to the curve of pressures— therefore heavy at breech and light at muzzle. See GUNS, NAVAL.