During the past fifteen years THE COMPUTER has been provided with great and revolutionary aids. The many volumes of W.P.A. Tables, sponsored by the National Bureau of Standards, have met a real need of long standing; the great automatic calculating machines have performed with ease and rapidity many calculations that were prohibitive in labor and time by the older hand methods and hand machines, and they have turned out volumes of tables in a matter of weeks; and, finally, the important journal Mathematical Tables and Other Aids to Computation serves as a clearing house in matters of computation and enables the computer to keep up with progress in computation throughout the world. The computer will be wise to make use of these aids whenever possible. It seems no exaggeration to say that during no other fifteen-year period in the world’s history have such great strides been made in the art of getting numerical results.