Inventions in the Century

by William Henry Doolittle

3. To provide a metal which should be at once stronger and safer than any which had been used before.

In the United States General Rodman, “one of the pioneers of armed science,” commenced about 1847 a series of investigations and experiments on the power and action of gunpowder and the strains received by every part of the gun by the exploding gases, of very great importance; and in this matter he was assisted greatly by Dr. W. E. Woodbridge, who invented an ingenious apparatus termed a “piezometer,” or a pressure measurer, by which the pressure of the gases at the various parts of the gun was determined with mathematical certainty.

Dr. Woodbridge also added greatly to the success of rifled cannon. The success in rifling small arms, by which an elongated ball is made to retain the same end foremost during its flight, led again to the attempts of rifling cannon for the same purpose, which were finally successful. But this success was due not to the spiral grooves in the cannon bore, but in attachments to the ball compelling it to follow the course of the grooves and giving it the proper initial movement. The trouble with these attachments was that they were either stripped off, or stripped away, by the gun spirals. Woodbridge in 1850 overcame the difficulty by inventing an improved sabot, consisting of a ring composed of metal softer than the projectile or cannon, fixed on the inner end of the projectile and grooved at its rear end, so that when the gun is fired and the ball driven forward these grooves expand, acting valvularly to fill the grooves in the gun, thus preventing the escape of the gases, while the ring at the same time is forced forward on to the shell so tightly and forcibly that the projectile is invariably given a rotary motion and made to advance strictly in the line of axis of the bore, and in the same line during the course of its flight. This invention in principle has been followed ever since, although other forms have been given the sabot, and it is due to this invention that modern rifled cannon have been so wonderfully accurate in range and efficient in the penetrating and destructive power both on sea and land.

Woodbridge also invented the wire-wound cannon, and a machine for winding the wire upon the gun, thus giving the breach part, especially, immense strength.

In England, among the first notable and greater inventors in ordnance during the latter half of the century, a period which embraces the reduction to practice of the most wonderful and successful inventions in weapons of war which the world had up to that time seen, are Lancaster, who invented the elliptical bore; Sir William Armstrong, who, commencing in 1885, constructed a gun built of wrought-iron bars twisted into coils and applied over a steel core and bound by one or more wrought-iron rings, all applied at white heat and shrunk on by contraction due to cooling, by which method smooth-bore, muzzle-loading cannon of immense calibre, one weighing one hundred tons, were made. They were followed by Armstrong, inventor of breech-loaders; Blakely, inventor of cannon made of steel tubes and an outer jacket of cast iron; and Sir Joseph Whitworth, inventor of most powerful steel cannon and compressed steel projectiles.

In Germany, Friedrich Krupp at Essen, Prussia, invented and introduced such improvements in breech-loading cannon as revolutionised the manufacture of that species of ordnance, and established the foundation of the greatest ordnance works in the world. The first of his great breech-loading steel guns was exhibited at the Paris Exhibition in 1867. A Krupp gun finished at Essen in the 70’s was then the largest steel gun the world had ever seen. It weighed seventy-two tons, and was thirty-two feet long. The charge consisted of 385 pounds of powder, the shell weighed 1,660 pounds, having a bursting charge of powder of 22 pounds, and a velocity of 1,640 feet per second. It was estimated that if the gun were fired at an angle of 43° the shell would be carried a distance of fifteen miles. It was in the Krupp guns, and also in the Armstrong breech-loaders, that a simple feature was for the first time introduced which proved of immense importance in giving great additional expansive force to the explosion of the powder. This was an increase in the size of the powder chamber so as to allow a vacant space in it unfilled with powder.

In the United States, Rodman, commencing in 1847, and Dahlgren in 1850, and Parrott in 1860, invented and introduced some noticeable improvements in cast-iron, smooth-bore, and rifled cannon.

In France General Paixhans and Colonel Treuille de Beaulieu improved the shells and ordnance.

The latest improvements in cannon indicate that the old smooth-bore muzzle-loader guns are to be entirely superseded by breech-loaders, just as in small arms the muzzle-loading musket has given way to the breech-loading rifle.

A single lever is now employed, a single turn of which will close or open the breech, and when opened expel the shell by the same movement. Formerly breech-loaders were confined to the heaviest ordnance; now they are a part of the lightest field pieces.