244 School Science and Mathematics
(3) JOHANSON, ELVY, Kiirsplanewidersokningar ifysik och kemi. Uppsala: Alm-quist & Wiksells. (1961). No English summary.
(4) WERDELIN, INGVAR, The Mathematical AbilityExperimental and FactorialStudies (IX. in Studio psychologica et paedagogica; series altera) Lund:C. W. K. Gleerup (1958).
(5) CARLI, 0., Vardagsrakning. Stitdieplan i matematik for nionde skoldret (Alter-nativktirs 2) vid pcdagogisk forsoksverlisamhet i overenstdmmelse mod beslut avIP 50 drs riksdag. Stockholm (1952).
(6) DALENIUS, T., Sampling in Sweden (Contributions to the methods and theo-ries of sampling survey practice). Uppsala: Akad. avh. (1957)
(7) KLEIN, J., Matematikknrsen pa enhetsskolans Jiogstadiiim Nagra synpunkter.Pcdagogisk debatt 6:14-17 (1958)
(8) STENMARK, H., Matematiknndermsningen i realskolan och motsuarande skol-former. (Skrifter utgivna av Svergies yngre laroversklarares forening) (15).Malrno (1956)
SATELLITES TRACKED FROM SPECIAL ARMY-NAVY SHIPFuture satellites will be tracked from the sea. An old World War II cargo
vessel, the USNS Kingsport, has been remodeled into a satellite tracking station.A dome-shaped structure on the deckhouse covers an antenna that can track asatellite in an orbit 23,300 miles above earth. .- .-The antenna in the dome is a 30-foot aluminum "dish" reflecting antenna. It
moves in three directions by gearless direct power, ijonbwirig a,satellite at anyangle above the horizon. Another antenna mounted xnrthe foremast receives andsends information to satellites.
Tracking the SYNCOM, National Space and Aeronautics Administrationsatellite to be launched in early 1963, will be the first project of the USNSKingsport.The vessel was designed by the Bureau of Ships in a Defense Department pro-
gram under the Army. It was operated by the Military Sea TransportationService.
NILE EXPEDITION FINDS CLUES TO ANCIENT CLIMATESThe Nile has provided a clue to ancient climate changes.A section of the middle Nile Valley scheduled to be submerged when the
Aswan Dam is built has given information about the rivers fluctuations as farback as 25,000 years ago.
Indications are that the periodic floodings and recedings of the Nile followworld sea-level variations. Both are in phase with changes of solar radiation. Thework on ancient climates is important in predicting the weather of the future overa long-range period.An American expedition measured the ages of silt deposits by radiocarbon
dating of marine animals and, even, an ancient campfire. Silt deposits were great-est during periods of little rainfall. The oldest silts are probably 25,000 years old.Studies indicated that the present level of the Nile was reached 5,000 years ago.It is thought that there have been long periods of high and low Nile floods.The Mesolithic and Neolithic artists portrayed a varied fauna life north of the
Nile from 7,000 years to 11,000 years ago. It is thought that the animal lifemigrated from Egypt, which was going through a period of heavy rainfall withseasonal monsoons during this period.