A-14 ROYAL SOCIETY OF CANADA. 



13th), according to astroiioinical reckoning, is on Thursday, June 14th, 

 civil time. 



In this we have the element of confusion, and it is not surprising 

 that the Washington International Conference of 188-1 recommended 

 that the civil day should take the place of the astronomical and nautical 

 days for all purposes. The recommendations of the Washington Confer- 

 ence must be held to carry weight, as this assembly comprised represent- 

 atives of science from twent^'-tive nations special I}- called together 

 to c<msider questions of Time-reckoning. Among them, were astrono- 

 mers of world-wide fame, as well as men who held high rank as navi- 

 gators. They were unanimous in the opinion that as soon as practicable 

 the astronomical and nautical days should be arranged everywhere to 

 coincide with the civil day. 



The civil day is the reckoning used by the generality of mankind. 

 It is the exact mean between the astronomical and nautical days, and 

 differs precisely twelve hours from both. To effect a complete coinci- 

 dence, it is only necessar}' to shift astronomical and nautical days each 

 tAvelve hours, and this shifting will bring both to the civil day. Many 

 ships have already abandoned nautical time and date their logs according 

 to civil reckoning; all ships would use the one reckoning only, if the 

 Xautical Almanac and Kphemerides generally were arranged for civil 

 time. There can be no doubt whatever that the marine of all nations 

 would benefit by the change. 



If we consider the subject simply in its relation to the Nautical 

 Almanac and navigation, the Unitication of Time-reckoning would 

 simplify the calculations of marinei-s and reduce the chances of error. 

 One correspondent (Dr. Johnson of McGill University) points out very 

 truly " that the omission of even a single step in an oft-repeated process 

 of calculation has an obvious advantage ; when the simplification 

 removes at the same time that most dangerous source of erroi', an ambig- 

 uous expression, it becomes a great gain." He says that the subject 

 resolves itself into a question of ])ractical utility, viz., what is the 

 greatest good of the greatest number? The Nautical Almanac, as its 

 name implies, is for the use primarily of mivigators, who ai-e very 

 numerous and yearly increasing. Compared with the men who guide 

 the floating tonnage of the world, astronomers are extremely few in 

 number, and astronomers as a class are skilled calculators ; moreover, 

 astronomers can make their calculations under the most favourable 

 circumstances, consequently with the least liability to error, as they are 

 removed from the disturbing influences to which seamen are frequently 

 exposed. 



The Joint Committee considered it important to ascertain how far 

 astronomers generally would support the proposal which would practi- 

 cally abohsh the astronomical day. On April 21st, 1893, a circular was 



