294 MEMOIR OF AUGUSTUS DE MORGAN. 



1858. If a year begin with a day there must be as many beginnings 



of years as there are beginnings of days. Now I ask another 

 question. From to 360 of terrestrial longitude, how many 

 meridians are there ? The political world will be content with 

 defining the year by the place. The astronomer, when he names 

 time, always names a place. If you like to begin the year with 

 the centre of the mean sun, in the mean equinox, it can be done, 

 but the poor almanac makers must not be puzzled, and I protest 

 against any more 185f , or the like. 



I returned to the Royal Society the other day a book which was 

 given to them in 1728, and had probably wandered the world for 

 more than a century. That book and others satisfy me that about 

 the years 1734-40 the R. S. library was expurgated purged 

 of all anti-Newtonian and infinitesimal books. This is curious, 

 but they were curious people in curious days. 



There is a very marked absence of all materials for studying 

 the Newton and Leibnitz controversy in the R. S. library. 



Yours truly, 



A. DE MORGAN. 



To Sir John Herschel. 



7 Camden Street, Feb. 11, 1858. 



MY DEAR SIR JOHN, I see your drift. But that year question 

 set me off on equinoctial time. Why, the question is an ethno- 

 logical, not an astronomical one. When the Portuguese and 

 Spaniards met in the Philippines via India the Portuguese, 

 via S. America the Spaniards they differed a day in their 

 reckoning, kept their Sundays on different days, and cursed each 

 other as only real Christians can curse. I never could learn how 

 the Pope settled it. 



Taking Christendom as a point of departure from whence all 

 have gone whom we are concerned with, we shall find the 

 Americans beginning their Sunday after us, and the Anglo- 

 Indians before us ; the New Zealanders after us, the Australians 

 before us, owing to the way they go. But when New Zealand 

 goes to Australia there is a change of day for them, and vice 

 versa. 



Rule. Do at Rome as they do at Rome. And what they do 

 at Rome depends on the direction of travel by which they got to 

 Rome. If there were a constant meeting at the meridians oppo- 

 site Christendom by people of different modes of coming there, 



