1872.] Engineering. 103 
English gun gave still higher performances. From these experiments it has 
been shown that the Prussian gun had reached its maximum range at 
3000 yards, as the curve of its trajectory is very high, whilst the trajectory of 
the English gun being much flatter is much in favour of the latter. 
During the last quarter the new 35-ton 7oo-pounder gun, known as the 
** Woolwich Infant,” has passed through the last stage of its trials at the proof 
butts, Woolwich Arsenal. At first the diameter of this gun was 11°6 inches, 
with which bore it gave very singular and uncertain results as regards pres- 
sures and velocities, and it was found not to consume the whole of its powder. 
In order to remedy these defects the bore was enlarged, by which means it 
was anticipated that the whole of the charge, being shortened, would be 
consumed, and that better results would be obtained. In its altered state it 
was tried, last October, with r1o lbs. and 115 lbs. powder charges and a flat- 
headed 700 lbs. projectile, when the highest initial velocity obtained was 
1355 feet per second with 115 lbs. of Belgian S.G. powder, the highest with 
Waltham L.G. powder being 1300 feet per second; but as the pressures with 
the Belgian powder were much higher than those given with the Waltham 
powder, even proportionately to the velocities, that disadvantage may be 
considered to more than counterbalance the slight increase in velocity. The 
carriage for this gun was designed by Captain R. A. E. Scott, R.N., upon his 
compound pivotting principle. The skeleton of the carriage is of cast-iron, 
plated with wrought-iron, weighing r1 tons, with gear complete, and measuring 
g feet in extreme length at thebase. The gun is carried in a saddle-piece, the 
ends of which work in slides in the cheeks of the carriage, and have a step 
arrangement for giving the gun three different planes of elevation. The 
results were, on the whole, satisfactory, notwithstanding some slight defeés 
discovered themselves, which were due chiefly to the manner in which the 
carriage was mounted. On the 5th of December, when the last rounds were to 
be fired previously to its removal to Shoeburyness, a defect was discovered in 
the steel lining of the bore. We shall have more to say on this subjeé@ when 
we give an account of the further experiments at Shoeburyness, which will 
shortly be carried out. 
Mr. Bessemer has recently published an account of his monster gun, by 
which the inventor anticipates that a weight of metal may be thrown far in 
excess of anything that has yet been attempted, combined, at the same time, 
with a lighter form of gun, requiring the employment of less metal in its con- 
struction. To achieve this end, he seeks to consume his powder charge in 
such a manner as to utilise the whole of its effective force, and, at the same 
time, to avoid throwing any sudden and excessive strain upon the gun. In 
the present system a given charge of gunpowder may exert at the moment of 
explosion a force of 60,000 Ibs. per square inch on the chase of the gun, and 
by the time the projectile has traversed a distance of 10 feet, the pressure may 
be reduced to a mean of 15,000 Ibs. per square inch through the entire length. 
Mr. Bessemer proposes to substitute for this violent and unequal action a 
continuous force of only some 3000 lbs. to the inch, maintained upon the shot 
throughout the entire length of its extended travel along the bore of the gun, 
hoping to obtain an equivalent duty with a vastly reduced strain. The inner 
tube of the gun may consist of several thick plates of iron, each bent into a 
tube, and welded, the inner and outer surfaces being bored and turned so as to 
receive a series of steel hoops placed on hot, and exerting an initial force on 
the gun. At the ends of the inner tubes are flanged hoops forthe purpose of 
connecting the several lengths together by bolts. The breech may be secured 
by a movable breech plug screwed into the end of the tube, and made gas- 
tight by an expanding metal elastic cap, forming a knife edge on the plug, and 
forced against a ring of copper, or other soft metal, let into a groove formed 
around the breech for that purpose. In order that a continuous supply of gas 
under pressure may be generated and made to aé on the projectile as it 
advances, a cartridge or powder chamber is provided, which fits loosely inside 
the gun; it consists of a cylindrical mass of steel, in which a large number of 
small holes or chambers have been drilled parallel to the axis of the gun. 
From 20 to roo of these chambers are made according to the size of the 
