LEGAL TIME IN VARIOUS COUNTRIES — PHILIPPOT. 249 



process, is one in which the uninitiated is very liable to make errors. 

 As the transformation is generally wished quickly, it is important to 

 reduce the process to its simplest state. Since the time defined by 

 the mean sun is itself purely conventional, it may be used over a 

 considerable region with little inconvenience. Thus, for the whole of 

 a country may be adopted either the time corresponding to some 

 point in its capital or to that of its principal observatory, whichever 

 is preferable. 



With the extension of international communication, quite naturally 

 certain countries grouped together in the use of the time correspond- 

 ing to some place near their center when this did not bring too great 

 discordance with the true local time. But this effected only a partial 

 solution and trouble still remained when it was desired to pass from 

 the time of one group to that of another. An international agree- 

 ment was necessary for considering this problem and bringing it to a 

 rational solution. 



SYSTEM OF ZONES DIAL OF 24 HOURS. 



In 1884, a conference, called together at the initiative of the United 

 States, met at Washington for the purpose of coming to some under- 

 standing among the various nations of the world as to the choice of a 

 standard meridian and a universal system of time. Several such 

 systems were proposed. The conference, which, moreover, had no 

 legal power, limited itself, among other resolutions, to recommending 

 the adoption of the meridian of Greenwich and to the expression of 

 their sentiment in favor of a universal system of time without com- 

 mitting themselves to any special system. However, during their 

 sessions the delegates planned a system of hour lunes or spherical 

 sectors, which was already coming into use in certain portions of 

 North America. According to this scheme, the terrestrial globe is 

 divided into 24 sectors, 15° or 1 hour in width; that which extended 

 7.5° or 30 minutes of time to the west and to the east of Greenwich 

 was adopted as the initial sector. The time in any sector is exactly 

 1 hour ahead of the neighboring sector just to the west and 1 hour 

 behind that just to the east. 



The advantage of such a convention is that at any instant the 

 time indicated by accurately regulated clocks the world over would be 

 the same as to minutes and seconds, differing only in the whole hours ; 

 consequently in passing from the time of one place to that of another 

 it is necessary to add or subtract only a whole number of hours. This 

 process consists in combining two numbers of never more than two 

 figures; thus the task is reduced to its minimum. 



Evidently such a simple system must finally prevail from its own 

 merits; consequently we find it coming more and more into use. 



