June ii, 1896] 



NA TURE 



127 



opinion. "The chanj,'e of calcnilar," says Prof. New- 

 comb, " met with much popular n|iposition, and it may 

 hereafter be conceded that in this instance the common 

 sense of the people was more nearly right than the 

 wisdom of the learned. An additional complication was in- 

 troduced into the reckoning of time without any other real 

 object than that of making Easter come at the right time. 

 As the end of the century approaches, the question of 

 making iqoo a leap-year as usual, will no doubt be dis- 

 cussed, and it is possible that some concerted action may 

 be taken on the part of leading nations looking to a 

 return to the old mode of reckoning."^ We are now 

 several years nearer that time tlian when these words 

 were written, but there is no proposition to return to the 

 Julian reckoning, whilst it seems likely that Russia, 

 which still observes it, will shortly adopt, either at once 

 or by degrees, the Gregorian style, in which case all 

 Christian nations will conform to its use. But it should 

 never be forgotten that Ca:sar's main object was to get 

 rid of the previous Roman complication between a solar 

 and a lunar year (endeavouring to keep them together by 

 the insertion from time to time of an intercalary month), 

 and substitute an entirely solar year with only an inter- 

 calary day every fourth year, making the length equal 

 to its true amount within a few minutes. 



But now comes the question. Is the so-called Gregorian 

 year absolutely exact.' Its length is unquestionably 

 nearer that of the true typical year than the Julian year 

 is. But a further modification is necessary if we really 

 desire to make the date of the year correspond with the 

 seasons for all time. The Gregorian rule amounts in 

 fact to considering the year to contain 365'2425o days, 

 whereas the typical year really consists of 365'24220 

 days, the difference being o'ooo30 day, and the Gre- 

 gorian year is too long by that amount. It in fact drops a 

 leap-year not quite often enough, and a better rule would 

 have been to drop one at the end of each successive 

 period of 12S years. M. Auric has therefore recently 

 suggested in the Comptes rendus of the French Academy 

 a modification of the Gregorian rule, which would render 

 it almost absolutely accurate, but which this generation 

 need not, and in fact cannot, decide upon adopting. In 

 3200 years there are twenty-five jieriods of 128 years, 

 so that there should be twenty-five omissions of leap- 

 years. But by the Gregorian rule, only twenty-four leap- 

 years are dropped in that interval, or one too few. His 

 proposition then is to make an additional drop or omission 

 of a leap-year in the year 3200 (which would, as the 

 Gregorian rule now stands, be a leap-year), and at every 

 succeeding period of 3200 years, \Vt. 6400, 9600, being 

 not leap-years. Strictly speaking, however, as the 

 Gregorian calendar was arranged to start from a.d. 325, 

 the first of these periods should expire more than three 

 centuries later than .\.D. 3200, and as .\.D. 3500 will not 

 be a leap-year by the Gregorian rule of dropping all 

 divisible by too without remainder unless also divisible 

 by 400, the nearest way to carry this proposal out prac- 

 tically would be to enact that .\.l). 3600 should be an 

 exception and not a leap-year ; M. Auric's rule being 

 afterwards applied at intervals of 3200 years, so that a.d. 

 6800 and .\.IJ. 1 0000 would not Ije leap-years, although 

 the Gregorian rule would make them so. 



The present writer ventures to propound his own view 

 that this same object would be carried out more straight- 

 forwardly by the natural course of dropping a leap-year 

 at the end of each period of 12S years as it was com- 

 pleted, making unnecessary the (Gregorian complication 

 of an exception of an exception /.<■. the usual leap-year) 

 now proposed to be increased by an exception of an 

 exception of an exception. How exact this one exception 

 would make the calendar (and M. Auric's suggestion 



1 Wh.it Prof. Xewcomb mr-ans he 

 the paschal full moon followed, fall o 

 the Nicsean council. 



would do precisely the same thing in a more roundabout 

 wa)') may easily be shown. By dropping a leap-year (which 

 usually occurs every fourth year) at the end of 128 years, 

 we obtain in that period ninety-seven common years of 365 

 days, and thuty-one bissextile years of 366 days, or 

 46,751 days in all. Dividing this by 128, it is seen that 

 this is equivalent to making each year contain 365'242I9 

 days, the true length of the tropical year being (as above 

 stated) 365'24220 days. It is agreed on all hands that 

 1900 is not to be a leap-year ; and the effect of acting on 

 this proposal would be that the next omission of a leap- 

 year after that date would be in a.d. 2028. 



W. T. Lynn. 



NO. 1389, VOL. 54] 



THE NICARAGUA CANAL} 



T^* HE author of this book, though originally an engineer 

 -'- by profession, has become a traveller, a newspaper 

 correspondent in Africa, the Far East, and Central 

 America, and a writer about Eastern countries and 

 problems. The book, accordingly, somewhat naturally 

 reflects the two-fold experiences of the writer. Nicaragua 

 is regarded, on the one hand, as the probable site of a 

 gigantic engineering undertaking for connecting the 

 Atlantic and Pacific, rivalling in commercial importance 

 the Suez Canal ; and the feasibility and prospects of the 

 proposed canal are considered from an engineering 

 standpoint, in combination with its commercial and 

 political aspects, which cannot be disassociated from the 

 more purely engineering problems involved. On the 

 other hand, Nicaragua is described, in four chapters in 

 the middle of the book, from the traveller's point of view : 

 and details are given of the manners and customs of the 

 population, the means of communication and resources 

 of the country, with descriptions of the principal towns 

 and other matters of interest noticed in the author's tour 

 through the country. This portion of the book will 

 possess attractions for readers of books of travel ; but it 

 appears to have been introduced rather with the object 

 of recording the facts casually collected by the author, 

 than as having any special bearing on the important 

 problem of interoceanic communication. The main 

 object of the book is unquestionably the Nicaragua 

 Canal ; and the Suez Canal has demonstrated that it is 

 quite possible to construct a highway for navigation in 

 a country devoid of natural resources, and that the 

 physical conditions of the site selected, and the climate, 

 are the main points which determine the feasibility of 

 isthmian canals. 



Several routes have been proposed for forming a water- 

 way across the isthmus of Panama ; but the only two 

 which have been deemed capable of practical adoption 

 are the line chosen for the Panama Canal, traversing a 

 narrow portion of the isthmus between Colon and Panama, 

 nearly following the course of the Panama Railway, and 

 the more northerly Nicaragua route crossing a much 

 wider part of the isthmus, in which, however. Lake 

 Nicaragua provides a considerable length of natural 

 water-way. The Paris Commission of 1879, presided 

 over bv M. de Lesseps, decided in favour of the Panama 

 route in preference to all the others, including Nicaragua, 

 mainly on the ground that it was essential that an inter- 

 oceanic canal, with prospects of a very large traffic, 

 should be an open water-way unimpeded by locks, like 

 the Suez Canal ; and Panama was the only route which 

 could possibly fulfil this condition. When, however, 

 owing to the treacherous nature of the soil under a 

 tropical rainfall, the unhcalthiness of the site when the 

 surface vegetation was disturbed by the excavations, and 

 the difficulties experienced in attempting to cope with the 

 floods of the river Chagres, whose course frequently 



1 *' The Key of the Pacific, the Nicaragua Canal.'* By A. R. Colquhoun. 

 Pp xiii -f- 443, with numerous illustrations, plans, and maps. (London: 

 .Archibald Constable .ind Co., 1895.) 



