We now learn that the Essen works have just begun the manufacture of a 314,600 pound gun. This piece, called "40 cm. kanone L/40," will, of course, be of 15.6 inch caliber, but it will differ from the one above described in that its length will be equal to 40 times the caliber, say 52 feet, or to the space occupied on the maneuvering ground by a field piece drawn by six horses (Fig. 1). This gun will be provided with two kinds of projectiles. One of these, called _light_, will be 3½ feet in length, weigh 1,628 pounds, and be capable of taking an initial velocity of 2,410 feet and of piercing, on its exit from the chamber, either a hammered iron plate 3¾ feet in thickness or two united plates 1¾ and 2¾ feet in thickness. The shell called _heavy_ will be 5¾ feet in length, and weigh 2,310 pounds, say more than a 4¾ inch siege piece! The charge employed will be 1,067 pounds of brown, prismatic Dunwald powder. Ten hundred and sixty-seven pounds--nearly half a metric ton, more than the weight of a field piece without its carriage! With this enormous charge, the heavy shell will be capable of an initial velocity of 2,100 feet and of piercing, on its exit from the chamber, either a hammered iron plate 4 feet in thickness or two united plates 2 and 2.88 feet in thickness. The _Cologne Gazette_, from which we borrow most of the data just presented, adds that the "40 L/40" piece will be the largest cannon in the world, but that it will not long enjoy the privilege of such pre-eminence. It appears, in fact, that Mr. Krupp is preparing to manufacture a gun of 17½ inch caliber, weighing 330,000 pounds. The projectile for this monster will be 6 feet in length, say the stature of a full grown man, and will weigh no less than a ton and a half. A man of medium stature will measure a little less than this projectile (Fig. 2). It is possible that all these figures have been slightly exaggerated by the ultra-Vosges journals, who doubtless intend to make an impression upon us; but we shall not dwell upon that point.