100 YEARS AGO

The most important archæological event reported from Egypt during the last excavation season (1903–4) is the discovery by Prof. Naville, of the University of Geneva, and Mr. H. R. Hall, of the British Museum, of the most ancient temple at Thebes… It is the funerary temple or mortuary chapel of the most distinguished monarch of the eleventh dynasty, Nebkherurä Mentuhetep, who reigned about 2,500 B.C.… So far as platform, ramp, and colonnades are concerned, this is precisely the arrangement of the great temple of Queen Hatshepset, or Hatasu, to the north… The curious plan of the great temple has puzzled archæologists and architects from Wilkinson's time to the present day. Whence this curious arrangement of platforms, inclined planes, and colonnades, so totally unlike anything else in Egypt? Various theories have been propounded, but it is only now that the solution has been found, owing to the discovery of the temple of Nebkherurä. Colonnades, platforms and ramps are then a feature of the older temple-architecture of Egypt; they were, at the time of the eighteenth dynasty, when the great temple of Hatshepset was built, old-fashioned, archaic, but it is evident that the great temple is, as far as its main arrangements are concerned, a mere enlarged copy of the thousand-year older temple at its side.

From Nature 16 June 1904.

50 YEARS AGO

The existence of a large number of discrete sources of extraterrestrial radio radiation (radio stars) has now been established. For the majority of the sources there is no information about their distance… The present communication describes a new method for the measurement of the distance of radio stars in the Galaxy, and gives preliminary results for the two intense sources in Cygnus and Cassiopeia. The method depends upon the absorption of the radiation from the radio stars by interstellar hydrogen at a frequency of about 1,420 Mc./s., corresponding to the spectral line of the ground-state of the neutral hydrogen atom. If the radiation from the source traverses neutral hydrogen in the Galaxy, it will suffer absorption at the line frequency, whereas its emission at neighbouring frequencies will be unaffected… Thus from observations of the spectral distribution and the magnitude of the absorption, the distance of the radio star can be estimated.

D. R. W. William & R. D. Davies

From Nature 19 June 1954.