lxxviii GENERAL SUMMARY OF SCIENTIFIC AND 



No. 57. Tables for finding the distance of an object by its 

 bearings; Practical papers of the Hydrographic Office; Nos. 

 I., II., IV. List of foreign lights, i. -iv. ; No. 54. Deep-sea 

 soundings in the North Pacific Ocean, obtained by the United 

 States steamer Tuscarora, Commander George E. Belknap. 



The "Nautical Almanac" for 1877 has been printed by 

 the Nautical Almanac Bureau, under the charge of Professor 

 Coffin. In addition to the usual regular components of the 

 volume, it contains corrections of the Ephemerides of Uranus 

 for the years 1873 to 1876 inclusive, prepared from Profess- 

 or Newcomb's tables; a table of logarithms of sines and co- 

 sines, with the argument in time; and tables for finding the 

 latitude of a place by the altitude of the pole-star. 



A new determination of the difference of the longitude be- 

 tween Washington and Greenwich has been made by the 

 Coast Survey, which, although very much the same as that 

 last obtained by that service, varies from what has previous- 

 ly been considered the true difference. 



The Deep Seas. The progress of geographical discovery 

 during the year has been largely connected with the opera- 

 tions of the Challenger and of the Tuscarora, so far as the 

 ocean is concerned, and those of the Austrian Polar expedi- 

 tion of the Tegethoff, although various interesting facts have 

 been added, from various regions throughout the world, that 

 tend to extend our knowledge of the subject. 



Messrs. Behm & Wagner have published their annual 

 summary of the population of the world, as obtained by the 

 latest reports and estimates, the footing for the year 1873 

 amounting to 1,300,000,000 souls. 



The movements of the Challenger, as being the most im- 

 portant expedition for oceanic exploration, continue to be 

 noted by all nations with great interest. This vessel reached 

 St. Simon's Bay, in South Africa, toward the end of the year 

 1873, and, after refitting, proceeded to Melbourne, visiting on 

 the way Kerguelen's Island, and other localities in the ant- 

 arctic seas proposed as stations for the parties engaged ir 

 the observation of the transit of Venus, arriving at Melbourne 

 on the 17th of March, her most southern latitude on the way 

 being 66^. 



Her programme, after leaving Australia, was to carry a line 

 of soundings to New Zealand and the Coral Sea ; next to 



