THE RELATION OF MEAN DISPERSION TO TOTAL SIZE OF SALVO PATTERN
By Lieutenant G.L. Schuyler, U. S. Navy
1. The total size of the salvo pattern—or the difference in range between shortest and furthest shots in a salvo—is perhaps the most readily appreciated measure of how close together the shots in it are falling. The "mean dispersion," or the average distance of the individual shots from the center of impact, is the best and usual measure, however, because, though a more abstract thing to visualize, it possesses certain advantages in facilitating the mathematical treatment of the subject. The relation between the two quantities "total pattern size" and "mean dispersion," is not a very generally appreciated one, as it is a part of the theory of probability in gun-fire which has only recently presented itself to us in a practical way.