Science: Millikan to Tasmania

Off for Tasmania last week with 225 rubber balloons, large tanks of hydrogen and a short-wave radio receiving set sailed hoary-headed Robert Andrews Millikan, pious physicist of the California Institute of Technology. With him went two brilliant young colleagues: Physicists Henry Victor Neher and William Hayward Pickering. For 18 years Dr. Millikan has carted his balloons through the snowy ranges of the Andes and Rockies, has plunged his flat, metal electroscopes 280 feet into snow-fed California lakes, to measure minute amounts of electricity which may penetrate their surfaces. Purpose of his travels: to learn something about the mysterious cosmic rays which seem to speed from interstellar space, and constantly bombard the earth.

Since he wishes to compute the different amounts of cosmic ray energy at a great variety of latitudes in both hemispheres of the earth, Dr. Millikan chose India, Australia and Tasmania for his latest researches.

In Tasmania for the first time, Dr. Millikan will use a new, streamlined cosmic ray counting apparatus. It is a light structure of four shelves, enclosed within an oval framework about three feet long, covered with black cellophane to keep out light. The two upper shelves in the black football each contain two Geiger counters, or ionization tubes which detect the arrival of cosmic ray particles. On the shelves below the counters are eight radio tubes. Connected to the counters and tubes is a light, compact short-wave radio transmitter with an aerial. When the apparatus is attached to a balloon and sent aloft, passage of the cosmic rays through the Geiger counters will be transmitted to the men on the ground through their short-wave receiving set, will be recorded on a slender tape. Disappearance of the apparatus after the balloons burst will be no great loss, for the scientists will have on their tapes a permanent record of cosmic ray activity.

With his new instruments Dr. Millikan hopes to measure not only the amount of cosmic ray radiation in the equatorial zone, but also the main direction from which the rays are coming.