SCIENTIFIC SUMMARY. 
277 
at the same time introduced, one which has hitherto proved fatal to the 
success of the air, or so called caloric engine ; — viz. : the inefficiency of the 
furnace. 
We discovered, soon after writing our last notice, that one of the Lenoir 
motors was exhibited at South Kensington, and occasionally at work there. 
It appears to be a perfectly successful application of the force of the explo- 
sion of measured volumes of coal gas and air, fired within the cylinder, by 
the ignition of the poles of a galvanic broken circuit at each end. 
Renewed attempts have been made to form an alloy of nickel and iron, 
similar to that found naturally in meteoric iron, which is known to possess 
great malleability and strength. During the Russian war, Mr. Fairbairn 
made experiments on various alloys of nickel with cast iron, but without 
obtaining any increase of strength. More recently, Mr. Longmaid has 
succeeded in alloying nickel with iron in the puddling furnace, producing 
a material more nearly resembling meteoric iron than that experimented 
on by Mr. Fairbairn. The Austrians are said to be using for their cannon 
an alloy called Aich metal, from the name of the inventor, and composed of 
copper 600 parts, zinc 382 parts, and iron 18 parts. Its tenacity and 
toughness are said to be very great. 
Guns andiron-cased Ships still attract the attention of engineers. A new 
form of rotating projectile, invented by Mr. Woolcombe, was described at 
the last meeting of the British Association. It is in form a thick zone or cir- 
cular disc, — in fact, it is cheese-shaped, with the centre of gravity eccentric, 
or not coinciding with the centre of figure. It is fired from a smooth-bore 
gun, in which two equal and parallel segmentsof a cylinder havebeen inserted, 
to reduce the bore to the same sectional form as the shot. In consequence 
of the eccentricity of the centre of gravity, the shot rotates in its flight, in 
a plane parallel to its faces, and perpendicular to its axis, and this alto- 
gether independently of any rifling of the gun. Hence, on the principle 
exemplified in the gyroscope, the axis about which the shot revolves will 
remain parallel to its first position throughout its flight, and some of the 
causes of deviation in ordinary round shot are counteracted. 
Renewed experiments at Shoeburyness, against a target of massive teak 
framing, with armour- plating resembling that of the Warrior and 
Minotaur , have shown that 4|-inch and 5^-inch wrought- iron plates 
can be easily penetrated by Mr. Whitworth’s steel flat-ended shells, fired 
from a 120-pounder gun, with charges of from 23 lb. to 25 lb. of powder. 
The 275 lb. shot from the Horsfall 13-inch smooth-bore gun, with a charge 
of 75 lb. of powder, was also fired at this target, and smashed through 
armour-plate, backing, and skin, carrying completely away several super- 
ficial feet of the target. The Whitworth shells, on the other hand, made 
comparatively clean punched holes, which it would not be difficult to plug. 
The difference of result is mainly due to the difference in diameter of the 
projectiles, causing fracture with Mr. Whitworth’s shells by punching, and 
with the Horsfall shot in a mode more analogous to cross-fracture. The 
difference of the charge of powder in the two cases must not, however, be 
overlooked. 
Thus the balance of superiority, which for a short time had rested with 
the iron- clad vessels, is now undoubtedly reversed, and the guns are 
