50 Years ago

A critical review of the methods of determination of the temperatures of ancient seas by the measurement of the oxygen isotopes ratio in fossil calcareous organisms is given by Y. A. Birstein (Priroda, 5, 21; 1959). It is based partly on the work published in the Soviet Union and it leads to certain new ideas regarding the origin of the deep sea fauna. Thus the author of this review is casting doubt upon the conclusions of C. Emiliani and C. Edwards ... regarding the sharp changes of sea temperatures during the late Tertiary era, and also about those of A. Fr. Bruun ... regarding the extinction of the deep sea fauna. According to the author all the deep oceanic regions must be considered to be regions of a relatively constant temperature, affording a place of refuge to many animal species which have eventually died out in the waters of a lesser depth.

From Nature 3 October 1959.

100 Years ago

The discovery of Halley's comet at a time so far preceding the date of perihelion passage adds another proof of the great capacity of the photographic method. The interesting point to many observers is as to when the comet will become visible to them as a telescopic object. This must, of course, depend in a large measure upon the diameter of their glasses and on their powers of vision. After the present moon has left the sky, say during the second week in October, the comet ought to have increased in light sufficiently for it to be observed in a 12-inch telescope. The calculated magnitude of the comet will be 141/2 on October 15, and its distance from the earth about 230 millions of miles ... The comet will be visible in an excellent position nearly all night during most of the winter, but will continue small and faint until it blazes out next April.

From Nature 30 September 1909.