80 UNIVEBSxVL OB COSMIC TIME. 



stood by the masses. The causes for sn oh a change to many will appear in- 

 sufficient or fanciful. In a few years, however, this feeling must pass away, 

 and the advantages to be gained will become so manifest that I do not doubt 

 so desirable a retorm will eventually commend itself to general favour, and be 

 adopted in all the affaii's of life. 



Be that as it may, it seems to me highly important that a comprehensive 

 Time-system should be initiated to facilitate scientific observations, and de- 

 finitely to establish chronological dates ; that it should be designed for general 

 use in connection with railways and telegraphs, and for such other purposes 

 for which it may be found convenient. 



Tlie Oosmic Day set forth in the recommendations would be the date for the 

 world recognizable by all nations. It would theoretically and practically be 

 the mean of all local days, and the common standard to which all local reckon- 

 ings would be referable. 



Vv ith regard to the reckoning of longitude, I submit that Longitude and Time 

 are so intimately related that they may be expressed by a common notation. 

 Longitude is simply the angle formed by two planes passing through the 

 earth's axis, while Time is the period occupied by the earth in rotating through 

 that angle. If we adopt the system of measuring Time by the revolution of 

 the earth from a recognized zero, one of these planes — that through the zero — 

 may be considered fixed ; the other — that through the meridian of the place — 

 being movable, the longitudinal angle is variable. Obviously the variable an- 

 gle ought to be measured from the fixed plane as zero, and as the motion of 

 the earth by which the equivalent time of the angle is measured is continuous, 

 the longitude ought to be reckoned continuously in one direction. The direc- 

 tion is determined by the notation of the Hour-meridians, viz., from east to 

 west. 



If Longitude be so reckoned and denoted by the terras used in the notation 

 of Cosmic Time, the time of day everywhere throughout the globe would in- 

 variably denote the precise longitude of the place directly under the mean 

 sun. Conversely, at the epoch of mean solar passage at any place, the Longi- 

 tude being known, Cosmic Time would be one and the same with the Longi- 

 tude of the place. 



The advantages of such a system of reckoning and nomenclature, as sug- 

 gested in the recommendations which I now submit, will be, I think, self- 

 evident. 



i;ecommexdatioxs tor the regulation- of time and the reckoning of 



longitude. 



1. That a stpsfem of Universal Time he established, imth the view of facilitating 

 sipichronous scientific observations, for chronological reckonings, for the purpose 

 of trade and commerce by sea and land, and for all such uses to which it is ap- 

 plicable. 



2. That the system be established for the common observance of all peoples, and 

 of such a character that it may he adopted by each separate community, as may 

 be found expedient. 



3. That the system be based on the principle that for all terrestrial Time-reckon- 

 ings there be one recognized unit of measurement only, and that all measured 

 intervals of Time be directly related to the one unit measure. 



4. That the unit measure be the period occupied by the diurnal revolution of the 

 earth, defined by the mean .solar ^passage at the meridian twelve hours /rojTi the 

 Prime Meridian established through Greemclch. 



5. That the unit m.easure defined as above be held to he a Day absolute, and 

 designated a Cosmic Day. 



6. That such Cosmic Day be held as the chronological date of the earth, chang- 

 ing with the mean solar passage at the Anti-meridian of Qreemoich. 



