The daily morning journal and courier., 1904-03-24

to suffer, since it's mass would now rep-
 resent only 400 times the weight of the
 projectile. A projectile of SAP 1-2
 pounds weight striking with a velocity
 of nearly l,640 foot-seconds would iln- part a velocity of nearly four foot-sec-
 onds to the mass of such a turret sup posedly suspended like pendulum. It is therefore dangerous to carry too far the tendency to reduce to min imum the weight of the armour plates with a view to reducing the weight of
 the ship as much as possible. Ship constructors will thereby produce tur-
 rets which will resist Derforation by
 projectiles, to be sure, but which will
 be in danger Of having their rotating
 mechanism put out of action from the
 shock of projectiles on the too light turrets.
 Under certain circumstances a heavl-
 CT turret formed of thicker armor of lower quality will be better than a tur- ret of lighter and better material. be- cause the greater mass of the former
 will give the whole a greater rigidity.
 Again. since the arnur of better quail ty-chrome nickel steel, for example is much more expensive, it may often be advantageous to use the cheaper ma terial in the interior, and the better ma
 terial on the exterior.
 But the most rational solution ap-
 pears to be to construct these arnored
 turrets by casting them in chrome nickel steel, either in the ordinary way or by hardening the surface. In Aus tria armored cupolas have been cast
 in this way since 1886, under the direc- tion of Col. Tilschkert, a high authori- i ty in the Austrian Army, and about
 nine years ago he proposed to harden 1 the surface of these cupolas by cast 1 ing them either in water or in oil; but this process was never applied, because 1 the resistance of the cupolas cast in the ordinary way and not hardened
 was found ample.
 1 In 1902. however, Krupp exhibited at
 the Dusselsdorf exposition cast armor
 plates of chrome nickel steel and
 proved to the world that these plates simply cooled have a resistance nearly 1 equal to forged and laminated plates. The cost Of tine latter, on account of the difficulty Of obtaining the desired
 curvature, is far greater than that of the former; moreover, the turret in the
 sormer can be given a spherical form, so that the proiectiles will always strike it at an acute angle, that is, with only about half the energy they strike a cylindrical turret, At the
 same cost, therefore, turrets are obtain ed which are more massive (and con- secuently more stable). and since the projectiles strike only obliquely the
 same thickness is not required as in cylindrical turrets. Instead of a weight of turret zoo times that of the projec- tile. one 400 times this weight will sur- flee; and this weight may even be con- siderably less, since a weight 25O times that of the projectile has been found sufficient for turrets of land forts. The naval turret of cupola (hemis- phericaD form appears therefore to be | A cylindrical turret of 440,000 pounds weight of nickel steel hardened. costs
 about $96,00O, without cost of founda- ton or cost of placing in position, while a turrets of cupola themisphericaD form. cast and hardened, without the addition of nickel, and of just as great resisting power, though weighing only