TRANSIT OF VENUS, 1874. 



PART III. 



EXPEDITION TO THE ISLAND OP RODRIGUEZ. 



SECTION I. POINT VENUS. 



PAGE 

 VOYAGE, PERSONNEL, SITE, INSTRUMENTS, AND GEOGRAPHICAL DETERMINATIONS : 



Voyage and Establishment at Kodriguez 351 



Personnel 353 



Site .353 



The Transit Instrument and Clock 354 



Equatorial intervals of Wires 355 



Collimation 355 



Error of Level 355 



Error of Azimuth 356 



The Altazimuth Instrument 357 



Euns of Micrometers 357 



Barometer and Thermometer 358 



Latitude of the Altazimuth Pier 358 



Longitude of Point Venus 358 



Longitude from Meridional Transits of the Moon . 359 



Longitude from observed Zenith Distances of the Moon 361 



Longitude from Occupations of Stars by the Moon 361 



Summary of these Results for Longitude 365 



Lord Lindsay's Chronometric Expedition to Rodriguez 365 



Report of Lieutenant C. B. Neate, R.N., on his Observation of the Transit of Venus, 



1874, December 8 365 



Equations resulting from these Observations 369 



MERIDIONAL AND ALTAZIMUTH OBSERVATIONS AT POINT VENUS IN TABULAR ARRANGE- 

 MENT : 



Table I. Collimation of the Transit Instrument 372 



Table II. Error of Level of the Transit Instrument 372 



Table III. Azimuth Error of the Transit Instrument 373 



Table IV. Meridional Transits (abstract) 375 



Table V. R.A. of the Moon's Limb (abstract, united with Table IV.) 375 



Table VI. Longitude of Point Venus from the Meridional Transits of the Moon . . 376 



Table VII. Abstract of Longitudes deduced from Vertical Transits of the Moon . . 377 



Plate XII. Plan showing the position of the Stations on Rodriguez .... to face 352 



Plate XIII. Diagrams illustrating the observation of the Transit of Venus by Lieut. Neate 366 



