alone out of six got its fragments just into the backing, seemed to show that the plate along the actual line of the "lap" was weakened by it. The second round was fired at the centre, and made, in common with all the other rounds, only a shallow indent. To determine whether the weakness caused by the "lap" extended beyond its immediate situation, the third round was aimed just to avoid it by about an inch, and from the result it was evident that the weakness was absolutely local, and that the “lap” had no tendency to produce cracking whether the blow was actually on it or very nearly so. Indeed, the face of the plate after six rounds showed no cracking whatever beyond a few superficial hair lines, and it is to be expected that when its back is seen, it will show five slight bulges, one hole (where the "lap" was struck) and no cracks. The information derived from those two trials on the experimental points referred to, is of considerable value, and the general result was very satisfactory.

-Engineering, September 3, 1897.

A Test of Krupp Armor.

In a recent reference made in The Iron Age to a test of a Krupp armor plate, the statement was printed that the plate in question was through cracked at the fifth shot. This was a mistake, since there were only surface cracks, quite a common appearance on surface hardened plates. Besides, the penetration of round five was only 4.1 inches, and not 7.7 inches as stated. It may be noted also that after the fifth round four additional rounds with 8-inch and 6-inch armor piercing shells were fired at the tapered part of the plate without cracking it. The point is made that the effect of round five does not give a correct idea of the power of resistance of the plate, since the points of impact of rounds one and five were too close together, their centers being only 16 inches apart. This part of the plate, therefore, had certainly lost the better part of its power of resistance before being struck by round five. The other points of impact were very close together, being about two feet apart from each other and from the edge of the plate. -The Iron Age, July 1, 1897.

c. Powder and Explosives.

Trials of Smokeless Powder, Manufactured by Max von Förster, Berlin, fired from Krupp's cast-steel 8.7 cm. Turkish field gun, on the prov

ing grounds of Tshataldja,, near Constantinople, August, 1897.

Weight of shell, 6.210 kg.

Temperature of air + 29° C.

Powder (smokeless) charge :—0 570 kg., velocity 25 m. in front of gun 446 m. 0.580 kg., velocity 25 m. in front of gun 454 m.

Difference between greatest and lowest velocity 7.4 m.

To obtain this velocity the regulation charge of the old smokeless powder would be 1.5 kg.

The gas pressures obtained were considerably lower than those caused by the old gunpowder.

;

The smokeless powder left no residue in the bore. No unconsumed powder grains (leaflets) remained in the bore nor were any found in front of the gun. Very little smoke. On opening the breech-block immediately after firing, no flame in rear, a moderate one in front of the gun.

The following tests were also made:

Firing for accuracy gave good results.

An endurance test of 75 shots, in order to determine whether the powder exerts any deleterious effect on the gun, particularly the bore. The 75 shots were fired in 11⁄2 hours. After every 15 shots the bore was washed out and examined.

After the firing was completed the bore was carefully inspected and measured. No alterations were observable nor any deleterious effects.

Firing with powder artifically dried and kept at + 55° C., also with powder exposed to very moist air. No abnormal shots resulted, although the pressure, in case of the warmed powder, was higher.

The chemical examination of the powder showed good stability in the acid test with zinc-iodide and starch paper, and a sufficiently high temperature of ignition, so that it could be definitely assumed that the powder will withstand all climatic action for many years.

No ingredients other than nitrated cellulose (guncotton) are found in the powder.

In conclusion, the trials showed that the smokeless powder furnished by the factory of Max v. Förster for the Turkish artillery, conformed to the conditions laid down for the delivery of the powder, and that it has no deleterious action on the guns.

-Deutsche Heeres-Zeitung, September 22, 1897.

Trials of smokeless powder, composed only of nitro-cellulose (gun-cotton) and manufactured by Max von Förster, Berlin, fired from the heavy field gun C/73 (Krupp's 8.8 cm. cast-steel gun), July 1897, at the factory's proving grounds (see preceding table).

During the past months 150 shots were fired from this same gun, without any effect on the gun, especially the bore. The powder does not strain the pieces (Krupp's cast-steel guns) any more than does any other smokeless powder, indeed, the strain is less than with the old gun-powder, since the same initial velocity is attained with less gas pressure.

-Deutsche Heeres-Zeitung, September 4, 1897.

FORTIFICATION.

The United States and Spain.

One of the first questions which naturally presents itself as of paramount importance to both sides, in the event of possible complications between Spain and the United States, is the relative and comparative position of these two powers as regards naval strength and value of coast defenses.

At first glance it would appear that Spain has chosen an inopportune moment to risk a conflict with the Great Republic of the New World. The United States has, since the year 1891, been putting forth every effort to overtake the general backwardness of her position as a naval power, which was the result of thirty years' absolute neglect of the fleet. In 1891 she did not possess a single battleship or cruiser, completed, of really satisfactory type. The most important vessels of her navy then approaching completion had been so long in building that they were practically obsolete, and the battle ships and cruisers of the new naval programme were not even laid down.

Since then, however, progress has been very rapid, the result being that at the present moment the United States can command, roughly, the above naval force of seagoing vessels.

In addition to the above, several powerful gun vessels of 1000 tons and over, of slow speed, are either building or just completed, and a number of older coast defence armoured vessels and older cruisers are on the lists, but we have only included the most recent and powerful warships. The torpedo boat flotilla is of no importance.

In order to rank against the above list of ten battleships and armored cruisers, and twenty ordinary cruisers, Spain can only show the following slender proportion of seagoing vessels actually completed and afloat, although a large number of ships have been laid down or launched within the past three years:

The cruisers of 1130 tons, which we have included amongst the Spanish vessels, are placed in the list because there are so many of them, but individual vessels of more importance are left out in the United States list. Spain has also a number of fast torpedo gunboats, a class which is not represented in America. She has also fourteen first class torpedo-boats built, and six building; two "destroyers" built, and four building.

As we before remarked, the first glance is very unfavorable to the relative strength of the seagoing Spanish navy when compared with that of the United States. Only eleven ships of real importance as regards tonnage and armament can be found to rank against the thirty which hail from the other side of the Atlantic. The superiority of Spain as regards her torpedo boat flotilla might give her a slight advantage upon the shores of her own continental dominions, as well as in the harbors and roadsteads of her island possessions. But she would be hopelessly outnumbered and overpowered at sea. A glance at the rates of speed, armament, and armored protection of the United States battleships and cruisers shows that individually and collectively the ships are immeasurably more powerful than those of Spain. So that it is quite clear that the command of the sea would fall into the hands of

America. That is to say, that if the two fleets were to meet at sea Spain would get the worst of it.

But this is a very limited view of the expression "command of the sea." In its fullest integrity this term implies that the Power which possesses such an attribute must have command of all seas in the vicinity of its territory. Look,. however, at the vast extent of seaboard possessed by United States. The most enthusiastic Yankee could never conceive that all these countless leagues of coast line could be protected and patrolled effectually by thirty sea-going war vessels; independently of the fact that a large number of them is required for foreign stations, so that the figures given have to be greatly discounted. Here, then, comes in the question of coast defences. What are the relative positions of the United States and Spain in regard to this rather important point? It is true that a very ambitious programme was issued in the States about two years ago, which provided for an enormous outlay on heavy guns and coast service howitzers to be mounted in batteries that should effectually seal the entrances to harbors and estuaries. But hardly any portion of the programme has been carried out. At San Francisco a number of pneumatic dynamite guns-seven, we think-has been mounted in emplacements which command the approaches, to supplement the existing batteries of coast guns and howitzers; but these last are said—on the authority of an officer of great experience in the United States-to be of the most inadequate description and worthless for defence; whilst the pneumatic "torpedo-thrower" is an untried weapon, so far as actual war service is concerned. The approaches to New York are protected by two or three batteries of heavy guns; but the position might be shelled with impunity in the absence of the fleet by vessels carrying long range guns; and the damage which might be inflicted upon the city and suburbs of New York would be immeasurably greater than the risk which the enemy might run of losing a vessel or two during the operation. It has always seemed to us to be a most unwise thing for the Government of the United States to be on bad terms with a Power possessing squadrons of any importance, whilst her coast remains practically unprotected, and her fleet has hardly emerged from the embryo condition. She is a great deal too vulnerable to be quarrelsome, and the only wonder is that the United States has not received a sharp lesson from one of the European Powers long ago. She has deserved it over and over again.

But, it may be asked, could not the Yankee fleet retaliate? And are not the coasts of Spain equally vulnerable? Certainly not. The 2122 kiloms. of coast line belonging to Spain, on the Atlantic and in the Mediterrenean, are generally of the most inaccessible and rugged description, and the rivers which run down to the coast line are mostly of a rapid and torrential character, certainly not lending themselves to the entrance of a hostile fleet. And Spain has paid particular attention to the question of coast defence for many years. Perhaps no country has taken more trouble than this in the perfection of coast battery protection, and she has had the best advice from the most important gun-making firms of Europe as to question of armament. Santander, a very important port, is protected by four strong forts, and Ferrol, which is the first naval arsenal in the kingdom, is surrounded with a network of forts and batteries, a system of detached forts being also under construction. Santona, although its defensive system is not yet fully completed, is a naval port of great strength and importance. There are also several other fairly

Journal 44.