74 GEOGEAPHICAL POSITIONS. 



No. 331, Broadway, by the mean of three distances of the sun and moon, appeared to be 

 74° 0' 42', and Mr. Nash adds, " I am inclined, for the present, to place the City Hall 

 in 74° W." 



By seventy lunar distances, forty of Pollux East, and thirty of Aldebaran West of the 

 moon, in December, 1822, and January, 1823, Captain (afterwards General Sir Edward) 

 Sabine gave the longitude of the cupola of Colombia College, New York, as 74° 3' 27", 

 and the latitude which he assigns to it is 40° 42' 43". Mr. De Witt, on his survey of the 

 province, gave the longitude as 74° 3'. 



The chronometers of Messrs. Arnold and Dent, however, appeared to have decided the 

 longitude of New York. Four of them were embarked in the British Queen steam-vessel, 

 under the care of Captain Roberts, on her first voyage from England to America, in 

 July and August, 1839, and gained the longitude of the City Hall in New York, as 

 4*^ 56™ 3-35= =: 74° 0' 49". A second experiment was made on the next voyage of the 

 same vessel, in October and November of the same year, by another set of four chrono- 

 meters, and by this the difference of longitude between the Observatory at Greenwich 

 and the City Hall, New York, appeared to be 4*^ 56" 0-24% say 74° 0' 10". M. Daussy, 

 the French Hydrographer, had previously given it in the Cvnnaissance des Temps as 

 4^ 56'" 0-72% or 74° 0' 11". 



By the determination of the United States Coast Survey, from data up to 1851, it was 

 in longitude 74° 0' 3'09" ; but, by the subsequent correction of the Cambridge longitude, 

 as shown before, it is in 74° 0' 15", as in the Table, very nearly identical with the deter- 

 mination of M. Daussy and Mr. Dent. 



4. Washington. — In our former editions, the Dome of the Capitol was placed in longi- 

 tude 77° 0' 20", agreeing closely with the State Survey of 1816. Later observations 

 place it in 77° 2' 0" W. 



Seaton Station, in the City of Washington, is the point to which all telegraphic 

 differences of longitude are referred, and which have now placed it in connection with 

 most of the important places on the Coasts of North-West America, and established, 

 beyond controversy, their true relative longitudes. 



5. NoBTH Carolina. — The longitudes of the coasts South of Cape Henry, at the 

 Chesapeake, as far as Cape Fear, or Section IV. of the United States Coast Sinrvey, are 

 dependent on that of Stevenson Point, the West Point of Little River, on the North side 

 of Albemarle Sound. The base line upon which the triangulation was established, was 

 measured upon Body Island, on the coast of Pamplico Sound, the South end of it being 

 near the Lighthouse. 



6. Charleston. — The longitude of Charleston was obtained from Seaton Station, in 

 Washington, by Electric Telegraph, in 1850, by Professor Walker and Lieutenant Gibbes. 

 Section V. of the United States Coast Survey system is thus connected with the rest of 

 the series. 



7. Cape Florida, &c. — In 1845, Captain Edward Barnett, R.N., made a running survey 

 of the Coast of Florida and the adjacent banks. His longitudes found by eight chrono- 

 meters by meridian distance from Havana, and in other portions of this region, have been 

 found very consistent. He placed Cape Florida in longitude 80° 3' 0" W. 



But the United States Surveyors maKe inis position a primary point for the longitudes 

 in Section VI. of the Coast Survey, and they made it, according to their estimate of 1851, 

 80° 5' 0", and in 1859, 80° 9' 29", or 6^' farther West than Captain Barnett. Yet Sand, 

 Kay was placed by the United States authorities, in November, 1852, as 81° 52' 43", while 

 Captain Barnett's longitude was 81° 51' 12", a difference of only 1^'. 



8. Key West. — The position of the Naval Storehouse was determined by United 

 States officers in 1875-6, the longitude being ascertained by electric telegraph. 



9. Mobile. — Fort Morgan, on Mobile Point, is made the primary station of Seotions 

 VIII. and IX. of the United States Survey, or between it and the Mexican frontier. 



10. New Orleans. — The longitude-of New Orleans is of some interest. The United 

 States Coast Survey assumed a considerable degree of importance from its extent, and 

 these results beine extended to the other portions of the territory, rendered the oon- 



