The Radio ball is unquestionably the hottest golf ball ever made - or that will ever be made! It has a radioactive center.

The June 1918 issue of Golf Illustrated [NY], advertised: “The quantity of radio-active substance which goes into one Radio Golf Ball. ...is the secret of this Ball of Mystery - the ball that never loses life or shape. $1 each, $12doz. John Wanamaker, New York, Sole Wholesale Distributor, U.S.A.”

A copy of this advertisement is included in the images of this ball, which is in outstanding condition with no strike marks as shown in the images. 

The Radio ball was patented in the U.S. by Ellis Miller, of London, England, who assigned his patent to The Radium Golf Ball Company, Limited, New York, N.Y. According to Miller’s patent (No. 1,260,788) granted on March 26, 1918, his ball has a round core formed from “radioactive material and an inert filling material” that retains the radioactive material in position and prevents its displacement.

The May 1918 issue of Golf Illustrated (ny) states that the Radio golf ball has a “Radium Center.” The article includes a “radiograph [x-ray] of the material used in the core of the Radio Golf Ball” (11). According to the June 4, 1918 issue of Golfing, the radium center used “radium salts”: “These salts have produced wonderful results in the intensive cultivation of crops, and their use in golf balls, though not giving any mechanical aid in the matter of distance, vitalises the rubber and keeps it in perfect condition.”

What a Killer Ball!