PREFACE. VI I 



difficult of occupation, Russia and America will apply 

 this very method ; while even the criterion devised to 

 minimise the value of the method, leaves it superior, 

 when applied at the stations I have indicated, to De- 

 lisle s, as applied at selected stations. 



I appeal to all who have influence in these matters to 

 examine the evidence for themselves (whether as pre 

 sented here, or with charts in my Essays in Astronomy, 

 or in recent numbers of the Monthly Notices of the 

 Astronomical Society), and to form their own judgment 

 as to the position of affairs. That is all I ask, since 

 I am satisfied that that will be altogether sufficient to 

 suggest the promptest and most energetic action.* 



EICHD. A. PROCTOR, 



LONDON: May 1873. 



* Since this was written I have received letters from the greatest master 

 of mathematical astronomy this country has produced since Newton s day, 

 strongly confirming my views as to the extreme importance of providing 

 many southern stations for applying Hall ey s method in 1874, and urging 

 me, moreover, to appeal to America to take part in this special work, for 

 which sJie is peculiarly fitted, because of the bravery and enterprise of her 

 seamen, the skill and ingenuity of her astronomers and physicists, and 

 her singular liberality as a nation in all scientific matters. 



