Dec. 31. 1853.] 



NOTES AND QUERIES. 



64^ 



together on the same day, if it be reckoned Mon- 

 day by the one, it will be reckoned Tuesday by 

 the other. They may differ as to Monday or 

 Tuesday, but they cannot rationally differ as to 

 whether it is day or night. 



It may be added that, no matter where these 

 two persons might meet, whether at the Antipodes 

 or at any other place, still, upon comparing their 

 journals, there would always appear a day's dif- 

 ference between them ; and if they were to keep 

 continually sailing on, one always towards the 

 west, and the other always towards the east, every 

 time they might meet or cross each other, they 

 would increase the difference between them by an 

 additional day. 



Whence it follows, that if two ships were to 

 leave England on the same day, one sailing east 

 by the Cape of Good Hope, and the other west by 

 Cape Horn, returning home respectively by the 

 opposite capes ; and if both were to arrive again 

 in England at the same time, there would be 

 found in the reckoning of the eastern vessel two 

 entire days more than in that of the western 

 vessel. Nor would this difference be merely 

 theoretic or imaginary ; on the contrary, it would 

 be a real and substantial gain on the part of the 

 eastern vessel : her crew would have consumed 

 two whole rations of breakfast, dinner, and supper, 

 and swallowed two days' allowance of grog more 

 than the other crew ; and they would have en- 

 joyed two nights more sleep. 



But all this is not an answer to H.'s question ; 

 what he wants to know is whether the day at the 

 Antipodes is twelve hours in advance or in arrear 

 of our day ? and, whichever it is, why is it ? 



But here H. is not sufficiently explicit. His 

 question relates to a practical fact, and therefore 

 he should have been more particular in designating 

 the exact habitable place to which It referred. 

 Our Antipodes, strictly speaking, or rather the 

 antipodal point to Greenwich Observatory, is 180° 

 of east (or west) longitude, and 51° 28' &c. of 

 south latitude. But this is not the only point 

 that differs by exactly twelve hours in time from 

 Greenwich ; all places lying beneath the meridian 

 of 180°, "our Periaeci" as well as "our Anti- 

 podes," are similarly affected, and to them the 

 same question would be applicable. H. is right, 

 however, in assuming that, with respect to that 

 meridian, the decision must be purely arbitrary. 

 It is as though two men were to keep moving 

 round a circle in the same direction, with the 

 same speed, and at diametrically opposite points ; 

 it must be an arbitrary decision which would pro- 

 nounce that either was in advance, or in arrear, of 

 the other. 



Regarding, then, the meridian of 180° as the 

 neutral point, the most rational system, so far as 

 British settlements are concerned, is to reckon 

 longitude both ways, from 0° to 180°, east and 



west from Greenwich ; and to regard all west 

 longitude as in arrear of British time, and all east 

 j longitude as in advance of it. And this is the 

 ! method practised by modern navigators. 



It is not, however, In obedience to any precon- 

 ceived system, but by pure accident, that our 

 settlements in Australia and New Zealand happen 

 to be In accordance with this rule. The last- 

 named country is very close upon the verge of 

 eastern longitude, but still it is within It, and its 

 day Is rightly In advance of our day. But the 

 first settlers to Botany Bay, In 1788, were actually 

 under orders to go out by Cape Horn, and were 

 only forced by stress of weather to adopt the op- 

 posite course by the Cape of Good Hope. Had 

 they kept to their prescribed route, there cannot 

 be a doubt that the day of the week and month 

 in Australia would now be a day later than It is. 



The best proof of the truth of this assertion is, 

 that a few years afterwards a missionary expe- 

 dition was sent out to Otaheite, with respect to 

 which a precisely similar accident occurred ; they 

 could not weather Cape Horn, and were forced to 

 go round, some twice the distance out of their 

 way, by the Cape of Good Hope ; consequently 

 they carried with them what may be called the 

 eastern day, and since then that is the day ob- 

 served at Otaheite, although fully two hours 

 within the western limit of longitude. 



From this cause an actual practical anomaly 

 has recently arisen. The French authorities in 

 Tahiti, In accordance with the before-mentioned 

 rule, have arranged their day by western longitude ; 

 consequently. In addition to other points of dis- 

 sent, they observe the Sabbath and other festivals 

 one day later than the resident English mis- 

 sionaries. 



I have extended this explanation to a greater 

 length than I intended, but the subject is Interest- 

 ing, and not generally well understood ; to do it 

 justice, therefore, is not compatible with brevity. 

 Much of what I have said is doubtless already 

 known to your readers ; nevertheless I hope it may 

 be useful in affording to H. the information he 

 required, and to Este more fixed notions on the 

 subject than he seems to have entertained when 

 he wrote the answer referred to. A. E. B, 



Leeds. 



PHOTOGRAPHIC CORRESPONDENCE. 



Aceto-Nitrate of Silver. — I have collected together 

 several ounces of aceto-nitrate of silver that has been 

 used to excite waxed paper (iodized by Mr. Crookes* 

 method), and should be glad to know whether it can 

 be used again for the same purpose. 



John Leachmak. 



[The aceto-nitrate may be used, but in our own 

 practice we do not do so. It is apt to give an un- 

 pleasant brownish colour. The solutions of silver. 



