RE 
RECKONING FOR THE TWENTIETH CENTURY. AT 
the revolutions of the globe. At no other point in the northern hemisphere are the con- 
ditions the same. A spectator standing at the north pole would have neither east nor 
west ; in whatever direction he might cast his eyes he would look towards the south; he 
would no longer see the daily return of sunrise and sunset; the sun when visible 
would move, or seem to move, in a horizontal line, and its path would encircle the earth 
parallel to and not far distant from the horizon. Under such circumstances it would not 
be possible to note the diurnal revolutions of the earth by the rising or setting of the sun, 
or by the sun’s greatest altitude at mid-day, or by his southern position in the heavens. 
As the passage of time can only be marked by events, what course could be followed ? 
Obviously it would be necessary to take special means to observe the earth’s diurnal 
rotation, and the method most readily to suggest itself would be to select a conspicuous 
object near the horizon and according to this object observe the sun’s passage over it. The 
object so selected would become the zero of time, and the interval between two succes- 
sive solar passages would be the period occupied by a revolution of the earth. If from 
zero the horizon be divided into a series of ares of 15° each, the whole circle around will 
consist of twenty-four divisions. If each of the division points be numbered from zero 
in the direction contrary to the motion of the earth or towards the right, and in imagina- 
tion the numbers be placed in a conspicuous manner against the sky, the spectator will 
have within his range of vision a great dial-plate on which as it revolves the vertical 
sun will continually point to the passing hours. With the twenty-four division points so 
numbered around the circle of the horizon, it is obvious that every hour in the day, and 
equally the smaller divisions of time, will invariably be manifested by the solar passage. 
As the imaginary point of observation, the north pole, is common to every meridian, 
the hours and minutes indicated by the great polar chronometer will be equally common 
to every locality on the surface of the globe. Whatever the longitude, the solar passage 
will be the index of time. Two successive passages at zero will complete an interval of 
twenty-four hours, but it will not be a day in the ordinary sense, as an ordinary day is a 
local phenomenon in no two longitudes identical.’ To distinguish this new interval of 
time common to the whole world from the infinite number of local days at present recog- 
nized, it has been suggested to term it the “Cosmic Day,” or some distinctive appel- 
lation by which it may be known. 
Necessarily the zero point must be arbitrarily selected according to convenience, and 
any zero whatever, other things being equal, would serve the purpose which we have in 
view. We have only to assume the zero so selected to coincide with the Antiprime 
Meridian determined by the Washington Conference, and the Cosmic Day will be identical 
with the Universal Day established under the same authority. A Universal or Cosmic 
Day may therefore be defined as the interval of time between two succeeding Solar pas- 
sages at the Antiprime Meridian common to all nations. 
In his recent discourse on the subject at the Royal Institution, London, the Astronomer 
Royal for Great Britain, Mr. Christie, expressed a preference for the term “ World Time” 
to designate this new measure of duration. It has been termed “ Cosmic Time” by various 
societies and individuals ; but the name is of secondary importance if it be understood that 

* The Nautical Almanic defines an ordinary Solar day to be the interval of time between the departure of any 
. meridian from the Sun and its succeeding return to it. 
