SUPPLEMEXTARY PAPERS. 33 



that in all countries in which hours are known, th-e origin of those hours 

 is, approximately, the mean time of local noon. There must thus be 

 introduced a degree of confusion, which the ordinary sense of man- 

 kind, by maintaining (in adjustments of public clocks, &c.,) the same 

 mean origin within definite limits, and well defined differences between 

 the indications in territories of other definite limits, has effectually 

 met. Thus the difference between England and Ireland has been 

 fairly met by a difference of 25"" (which would better have been 30™) 

 between the indications of the public clocks. It is, I believe, certain 

 that this is not the result of legislation, it appears to be merely the 

 result of common sense, guided perhaps by a single personal influence. 

 At Basle (possibly in like manner at other stations) the great systems 

 of the French Railways meet, and there the times in the French 

 States and the German States (I su2)pose Paris time and Berlin time), 

 are exhibited side by side, and there can be no confusion or difficulty. 

 In the case of the railway from New York to San Francisco, it is 

 merely necessary to frame the Westward train-bills and guard's 

 watches to New York time, and the Eastward train-bills and guard's 

 watches to San Francisco time, with double clocks at every station, 

 naturally there must be a re-adjustment of watches at the end of the 

 journey. Thus, adopting as incontrovertible the idea that every district 

 will refer to visible noon for the origin of its own time, and remarking 

 the extreme facility with which those origins can be linked together, 

 I set not the slightest value on the remarks extending through the 

 early parts of Mr. Fleming's paper. Secondlj^, as to the need of a 

 Prime Meridian, no practical man ever wants such a thing. If a 

 Prime Meridian were to be adopted, it must be that of Greenwich, 

 for the navigation of almost the v/hole world depends on calculations 

 founded on that of Greenwich. Nearly all navigation is based on the. 

 Nautical Almanac, which is based on Greenwich observations and 

 referred to Greenwich Meridian, and the number of Nautical 

 Almanacs sold annually exceeds, I believe, 32,000 (see the Navy 

 Estimates). But I, as Superintendent of the Greenwich Observatory, 

 entirely repudiate the idea of founding any claim on this. Let Green- 

 wich do her best to maintain her high position in administering to 

 the longitude of the world, and Nautical Almanacs do their best, and 

 we will unite our efforts without special claim to the fictitious honour 

 of a Prime Meridian.* For the mere expression of longitudes, with 

 the limitation that longitude is not to exceed 180° East or West, 

 Greenwich is not inconvenient. But every such consideration yields 

 to historical or other circumstances. Thus, as regards California 

 civilization and time-reckoning (in the count of days of a month) 



* The origin of Greenwioli Observatory is curious. A Frenchman l;ad a correct idea that 

 longitude at sea might be determined by observations of the mcvon. He was not received by 

 Louis XIV., but procured introduction to the Duchess of Portsmoutli, wlio placed his scheme 

 before Charles II. and his brother James, both able men in some respects. They adopted it, in 

 essentials, and Greenwich Observatory was founded. The moon is still tlie most important 

 object of the Greenwich Observatory. 



