DEAR ST. NICHOLAS: In your February number are two letters about curved pitching: one written presumably by an army officer, from Fort Monroe,—the other from Philadelphia, presumably by a naval officer. The army man states facts, and gives no explanation; the navy man fails to solve a well-known problem. In the days of smooth bores and spherical cannon-balls (round like a base-ball, only larger), eccentricity, or difference between the position of the center of figure and center of gravity, or weight, had a very perceptible effect upon range and accuracy. Placing the projectile in the gun, with the center of gravity to the right, when the gun was fired, the projectile or cannon-ball took up a motion of rotation from left to right, and deviated to the right (Fig. 1); placing it toward the upper part of the bore, the ball rotated from down up, and deviated upward, or the range was increased (Fig. 2). [Illustration: FIG. 1—VERTICAL. FIG. 2—HORIZONTAL. C. Center of shot. G. Center of gravity. A. Half ball moving toward the resisting air. B. Half ball moving away from the resisting air.] All bodies free to move will follow the line of least resistance. The force acting upon the ball (the resultant of the forward movement, and the opposing resistance of the air) will be _away_ from that half of the ball moving _toward_ the resisting air, as the ball, in its effort to take up the line of least resistance, is pushed away; no part of it is retarded. This it what a “curve-pitcher” does. A billiard ball having received a strong “draw,” or backward rotation, striking another to one side of the center, makes a very perceptible curve after impact, until the original motion of translation has been overcome. All these things were known before curved pitching ever was spoken of. Curved pitching was discovered accidentally, although, strange to say, many base-ball players were known always “to throw crooked,” or with a curve. Yours truly, E. B. BARRY, Lieut. U. S. N. * * * * * BRIDGEPORT, CONN. DEAR ST. NICHOLAS: Having seen so many articles in your “Letter-box,” on Mr. Harvey’s excellent story, “How Science Won the Game,” I thought I would write to you in regard to it. I have carefully tried the experiments of throwing the ball so that it would twist in the directions indicated by the different writers, and so far but one method has been correct in every particular; namely, the one given by F. C. J. in the May number.