From the September 24, 1932, issue

PREHISTORIC ROCK FORTS FOUND ON BARREN ARCTIC ISLAND

Reports of finding inaccessible rock fortresses in the sea, used by people of the Far North many centuries ago, are brought back from Kodiak Island, Alaska, by Dr. Ales Hrdlicka of the U.S. National Museum.

Dr. Hrdlickas discovery reveals for the first time that inhabitants of the North in ancient times had to take extreme methods of protection, very much as Pueblo Indians in the Southwest entrenched themselves on mesa tops. The fortresses discovered in the North are rocky islets off Kodiak Island coast. On the flat summits of these high cliffs, Dr. Hrdlicka discovered ruins of villages strategically placed by the ancient people who had some formidable enemy to fear, perhaps because they had enviable wealth in sea otter skins.

Among the carvings of fossil ivory is a portrait of a man, so cleverly carved that it must take rank among the fine art of prehistoric America. It is a true portrait, not a mere representation of a man.

The curling lip, which gives such an expression of disdain to the face, is due to a round ornament inserted in a slit in the lower lip. Eyes of the portrait were probably of stone, but these were missing when the ivory head was unearthed. Holes in the sides of the head indicate that the likeness was intended to be worn on a string, probably around someones neck.

FIVE DIGITS ARE TOO MANY FOR AUTO LICENSE TAGS

More than four numbers on a license plate makes it impossible to catch speeding drivers by noting their numbers, Dr. James L. Graham, of Lehigh University, warned psychologists at their recent national meeting in Ithaca. A specially devised apparatus with a reducing lens, which changed the apparent distance, made it possible to test in the laboratory ability to read plates rapidly fading into the distance.

With three-number plates in black letters on a white ground, 94 percent were seen correctly, but only 9 percent of seven-number plates were legible. Only 64 percent of five-number plates could be read, although the speed used in the laboratory was only a third to a fifth of usual road speeds, Dr. Graham found.

Bright reflecting surfaces greatly reduce legibility, he said, and color is also important. When lighted only by the taillight, blue on orange background is about 30 percent better than the same colors reversed.

ANOTHER STEP TAKEN TOWARD ABSOLUTE ZERO

Absolute zero, the completely cold point at which all temperature ceases, is only seven-tenths of a degree beyond the reach of physics now. Absolute zero is 273 degrees Centigrade below the freezing point of water; and Prof. W.H. Keesom of Leiden University has succeeded in producing a temperature of minus 272.3 degrees.

This is one-tenth of a degree lower than the previous record. A tenth of a degree does not amount to much at ordinary temperatures, but when the almost unattainable cold of absolute zero is the goal, the last few tenths of degrees are like the last few hundreds of feet to alpinists trying to climb to the summit of Mount Everest.

Prof. Keesom obtained his low temperature by keeping a small quantity of liquid helium constantly stirred while he produced a high vacuum over it by means of a pair of powerful mercury pumps.

NEW ATOMIC PARTICLE SUGGESTED BY EXPERIMENTS

The probable existence of a new particle of matter is reported by Dr. Carl D. Anderson of the California Institute of Technology, who works in association with Dr. Robert Andrews Millikan. It is a positively charged particle of the mass of the familiar negative electron. The usual positive particle is the proton that has a mass 1,850 times that of the electron.

The evidence for the new lightweight positive particle is contained in several photographs made while measuring the energies of charged particles produced by cosmic rays. Some tracks were found that seem to be produced by the new positive particles. The only alternative, Dr. Anderson states in his report to Science, is that two electrons made independent tracks on the photographs as they had the same point of origin. This probability is very unlikely.