200 
POPULAR SCIENCE REVIEW. 
SCIENTIFIC SUMMARY. 
ASTRONOMY. 
The Ap’proaching Transits of Venus . — The subject of the approaching 
transits of Venus is again attracting marked attention among astronomers. 
It will he remembered (see our Summaries of Astronomy ” for the year 
1869) that four years ago Mr. Proctor in England, and M. Puiseux in 
France, independently and almost simultaneously pointed out that the 
Astronomer Royal had made a serious mistake when he concluded that 
Halley’s method “ fails totally ” for the transit of 1874. In the discussions 
which followed in the Royal Astronomical Society and elsewhere, this im- 
portant point was tacitly conceded, and an effort only made to maintain that 
Delisle’s method is as good, or nearly so. Of course this is a detail altogether 
insignificant. If it be once admitted that Halley’s method is advantageously 
applicable, then whether Delisle’s is as good, or slightly better, or slightly 
inferior, the former method ought certainly to be applied. For, as every 
one knows who has studied the history of astronomical researches to 
determine the sun’s distance, the great point has always been, and must still 
be, to attack the problem in every possible way. Moreover, the Astronomer 
Royal, by advocating the employment of Halley’s method in 1882, although 
it will then certainly be inferior to Delisle’s, has indicated unquestionably 
the line which should be taken in 1874, now that Halley’s method has been 
shown to be advantageously applicable during the earlier transit. It 
chances that the station most suitable for applying Halley’s method in 
1874 is that very station — Possession Island, near South Victoria Land — 
where the Astronomer Royal and the most eminent geographers and naval 
officers had decided that we ought to have a wintering party in 1882. 
Nevertheless, incredible as it may appear, nothing whatever has been done 
during the last four years to repair the blunders made in 1857, and left un- 
corrected for twelve years. It is still Great Britain’s purpose, as originally 
suggested by the Astronomer Royal, to occupy five stations for applying 
Delisle’s method, although four out of the five can be as well occupied by 
other countries, whereas no other country but Great Britain is bound in 
honour to occupy Possession Island, What renders the matter more serious 
by far, is that Russia is doing her duty in occupying a most unpleasant 
station in Siberia, solely for applying Halley’s method. This station is 
Nertchinsk, the very spot pointed out as best by Mr. Proctor four years 
ago. Of course, without a suitable southern station, observations at the 
northern station will be thrown away. Yet, at present, Kerguelen Land, 
