The Works Of Messrs. Schneider And Co.

THE PROVING GROUNDS. 175 the installation in 1897, by adding the required plant for the manufacture of primers, firing tubes, fuzes, &c; The proving ground is located on the mouth of the Seine, and on its right bank ; it is in communication with the Havre Works by a road and a railway. Heavy guns are carried from the works to the proving ground on special trucks. Figs. 585 and 586 illustrate types of trucks made by Messrs. Schneider and Co. for the transport of heavy guns. The proving ground is so arrange«! tliat guns of all initial velocities of projectiles. For this purpose the usual range-finding and velocity screens are used, in conjunction with the Boulanger-Berger chronographs. The proving ground is completely equipped with all kinds of devices and accessories required for fully ascer- taining the working of guns, such as crusher gauges for measuring inside pressures, registering manometers for testing the pressure produced in hydraulie recoil cylinders, velocimeters for measuring gun-carriage recoil, &c. During the firing in the sand butts and at long range, at elevation Fig. 585. Fig. 586. Railway Trucks for Transporting Heavy Guns. calibres can be tested in every possible manner for ascer- taining their ballistic qualities, thøir range, accuracy, power of résistance under every practical condition, and so forth. The polygon is provided with several platforms ; five ! of these are arrangée! for point-blank firing against sarid butts ; two others, placed on the Seine enfbankment, are | specially adapted for firing at varions angles and degrées of elevation. Guns can therefore be fired at Havre under all conditions that would be required of them in actual warfare. The practice at the'sand butts serves to measure the or depression, the working of every part of gun and carriage is carefully examined and recorded. Special care has been taken for ail tests to be carried out with every possible guarantee of safety. There exista a system of signals for giving due notice when firing tests are going to take place, and casemates are built to shelter the personnel in charge of such tests. By means of an arrangement of mirrofs, the firing staft can witness in safety the progress of varions tests. Guns are fired from a distance, whether electric or percussion fuzes are used. The powder magazines are situated on the opposite