No. 6 fire at plates: Salvo of one 10-inch and one 11-inch shot at Marrel iron 22-inch plate, No. 1 target, lower portion, third series. A huge mass of iron was dislodged, and a crack was formed from bolt-hole to toward top edge of plate; penetration not quite so much as in Cammell's plate. The iron of the plate was heard to sing. The general quality of it appeared decidedly more steely than that of Cammell's plate. The 100-ton gun was now fired at an earth-butt 52 feet thick and 27 feet high, with results given in table, No. 11 round.

No. 7 fire at plates: The 100-ton gun was next fired with 340-pound charge at the Schneider steel plate, which had hitherto been left untouched. The effects are shown generally in lower portion of No. 2 target, fourth series. The plate was smashed to pieces, but the shot had broken up, and had not penetrated through the backing. The whole target had been driven 8 inches back, the inner skin was bulged and opened, and the angle-iron torn and twisted. For units of work and pressure, &c., see table No. 12.

On the 27th-No. 8 fire at plates: The 100-ton gun was fired at the Cammell iron plate, with results indicated generally in the upper half No. 1 section of No. 4 series. For charges, see No. 13 in table. Half the plate was struck away, leaving the wood bare. A part of the shot passed completely through the target, having a velocity measured at 600 feet on the far side. A hole was made nearly 4 feet in diameter, showing débris of broken iron and wood in interior. The following round was fired at the steel target, but the shot broke up in the bore of the gun.

No. 9 effective fire at plates: The 100-ton gun was next fired at Marrel's target, on the lower half of the same structure as Cammell's. (See No. 1, series 4.) The whole knocked into ruins. The shot passed completely through, leaving a large hole in the center, as in the case of Cammell's, showing the same heap of débris. For charge, velocity, &c., see No. 15 on table. No. 2 engraving shows the state of the targets at this stage of the proceedings.

No. 10 effective fire at plates was from the 100-ton gun at the upper half of Schneider's steel target. For effects, see No. 2 in No. 4 series. Although this plate had suffered severely from the fire of the smaller guns, complete penetration was not obtained. The plate was shivered into fragments. The head of the projectile remained buried in the backing. A considerable part of the body of the shot had been projected outward and bent forward without entirely separating from the head, (vide figure) a most unusual circumstance with chilled shot.

On October 28-effective fire No. 11 at plate: 10-inch gun at Cammell's sandwich target. Effects, see No. 4 and No. 2 series. Shot-head penetrated 13 inches, the metal remaining in the hole. One bolt started in the rear.

No. 12: 10-inch gun at Marrel's sandwich target. Effects, see No. 3, second series. Shot penetrated 10 inches only, but the plate was split in several directions, some pieces being nearly detached. Cracks through upper bolt-holes.

No. 13: Salvo of one 10-inch and one 11-inch gun at Marrel's sandwich target. Ef fects, wide fissures opened in plate 5; large pieces of plate and some small ones dislodged altogether and thrown on the ground.

No. 14: Salvo of one 10-inch and one 11-inch at Cammell's. Both shots pierced front plate, and penetrated 2.4 inches into rear plate; right-hand corner of plate dislodged; backing moved; one bolt sheared and broken, and one bolt-head forced into interior. (See section 3 in No. 4 series.)

No. 15: The 100-ton gun at Marrel's sandwich plates as injured above. Effects the main part of the target carried away, and complete penetration obtained. (See 3 in No. 4 series.)

The remainder of the rounds detailed in the table were then fired from the 100-ton gun.

In reviewing the plate-firing, the principal features to notice are the following: Series Nos. 2 and 3 show that steel is more liable to be destroyed by the fire of guns not capable of penetrating it than wrought iron,* which under these circumstances suffers but little.

Series No. 4 shows that steel, by transmitting the blow of impact through the plate, is less liable to let the shot through the backing, while more liable to be stripped off and destroyed itself.

It also appears obvious that the Duilio's power of offense will be greatly in excess of her powers of defense.

Engineering says that in comparing the results of the thirty-fifth round with those afforded by the 81-ton gun, firing 370 pounds of the same powder and a 1.700pound projectile, it will be seen that there is a preponderance of energy greatly in favor of the 100-ton gun. The 81-ton gun gave a velocity of 1,520 feet to its 1,700pound shot, with an energy of 27,200 foot-tons, or 540 foot-tons per inch of circumference of the shot. The 100-ton gun gave a velocity of 1,543 feet to a 2,000-pound shot, with an energy of 33,000 foot-tons, or 623 foot-tons per inch of circumference.

*The steel used was evidently not the best adapted to the purpose.-J. W. K.

THE DANDOLO.

These artillery experiments conducted at Spezia by the Italian government are by far the most important ever undertaken. Not only is the greatest gun ever made being tested for velocity and penetration, but armor-plates of different kinds and of almost unparalleled magnitude are tried for resistance and durability. The interest felt in the experiments by all naval authorities is not due alone to the performance of a single gun, but to the undisputed fact that the Spezia trials must exercise a powerful influence on the warfare of the future. Guns, ships, and armor will all undergo modifications.

The Duilio is to be armed with a heavy projecting ram, and she is also to be provided with apparatus for discharging the Whitehead fishtorpedoes. Besides these powerful means of offense, there is to be novel and original arrangement of carrying a rapid torpedo-boat; this boat is to be inclosed at the stern in a tunnel closed by a grated door, and when necessary can be launched and started on its course against an enemy's vessel.

The ship is to be driven by twin-screws. The motive machinery is furnished by Messrs. John Penn & Son, of Greenwich, England, and consists of his old type, a pair of trunk-engines to each screw. The steam will be supplied by the ordinary box-boilers. The two sets of engines are designed to develop the aggregate power of 7,500 horses, and the estimated speed of the vessel on the measured mile is 14 knots per hour. The heavy forgings for the ship were made in Italy. The frames, beams, and plates for the hull, in fact all the iron and steel entering into the construction of the vessel, were being made in France. All the armor-plates were ordered from Cammell & Co., of Sheffield, England, and the guns and machinery for working them were also to be of English manufacture, thus leaving only the construction and labor entering therein to be performed by the Italian engineers. The Duilio will be armed with four of the heaviest and most powerful guns ever mounted on any ship, and if completed and successful in all respects, she will be the most formidable fighting-machine, both for offense and defense, ever set afloat in the waters of continental Europe. When launched, the draught of water was found to be just what the designer estimated it would be, and it remains to be seen whether the prediction of the eminent ex-chief constructor of the British navy will be fulfilled, viz, that she will capsize in the first engagement, if seriously injured by shot in the unprotected parts.*

THE DANDOLO.

This sister-ship to the Duilio is under construction at Spezia, but is very far from being in the advanced condition of that vessel, and will not probably be completed in several years, as the financial resources of the Italian admiralty will doubtless be taxed to the utmost during the coming two years to complete the first of the great ships. The Dandolo is to be, in essential features of construction, the same as her sister, but an important distinction is in the motive machinery. This has been designed and finished by Messrs. Maudslay, Field & Son, of London, and consists of a pair of their inverted vertical compound engines to each of the two screw-propellers. The engines are to be supplied with steam from eight boilers fired from both ends, having in all thirty-two furnaces, four of the boilers being located forward and four aft of the engines. For the drawings of the Dandolo, Tegethoff, Shannon and Nelson, I am indebted to Monsieur P. Dislere, of the naval department, Paris.

S. Ex. 27-11

The pressure of steam is to be sixty pounds per square inch, and th maximum indicated horse-power the same as is intended to be develope in the Duilio.

THE CRISTOFORO COLOMBO.

This vessel, of the rapid type, building at Venice, is a wooden corvett but having iron beams and iron knees. The exact data were n obtainable, but they are nearly as follows:

Length....

Breadth.

Draught of water aft

Draught of water forward.

Fe

The hull is composed of Italian seasoned oak, put together in strongest and very best manner. The air-ports are much larger t are found in any of our own vessels; the quarters exceedingly comf able, and the interior well arranged in all respects. The battery consi of two rifled guns on each broadside and one bow-chaser. The mot machinery was constructed by Messrs. Penn & Son, of England, and e sists of one pair of their patent inverted vertical three-cylinder engines, plied to a single screw, and so arranged as to be worked either on the o pound or on the non-compound system, as desired. They were desig to develop a maximum indicated horse-power of 4,000, and the maxim speed of the vessel on the measured mile was estimated at 17 km But neither the constructors of the machinery nor the naval archite with whom I conferred believed that the hull had sufficient strengtl sustain for any lengthened period the power necessary to produce knots per hour.

DOCK-YARDS

The naval dock-yards of the kingdom of Italy are at Venice, on Adriatic; Castellamare, on the Bay of Naples; and Spezia, betw Leghorn and Genoa, on the Mediterranean.

VENICE.

The dock-yard at Venice was in ancient times, as at present, kne as the arsenal. There is no spot in Venice more intimately connec with the times of her powerful grandeur. It was considered one of most important elements of the power of the republic. Here were structed the galleys so celebrated for their strength and lightn Not only were all the stores required in war preserved here, but eve thing warlike was manufactured within its walls. Before the princi gate, as if to guard it, stand four marble lions, spoils taken from c quered nations. The ancient walls still remain; also many of the fort buildings; but they have been internally reconstructed, to suit the ma varied and wonderful changes in naval architecture since the days the Doges. The estimated area within the walls is about one hund acres. The basin area is very considerable, and one superior stone dry-do is completed, and a second is under construction. The appliances a machinery are as yet rather primitive. The few tools and machinery value in the buildings of the engineering department are of Engl manufacture. In fact, none of the buildings contain appliances wo noting.