352 TRANSIT OF VENUS, 1874. RODRIGUEZ. 



pair of sheers stepped on its edge. The operations of landing and placing 

 the instruments, huts, &c., were performed by the officers and men of H.M.S. 

 Shearwater, under the superintendence of Commander "Wharton. 



" During the sojourn of the party on the island, observations for local time 

 were made on every fine night ; the Moon was observed both with the transit- 

 instrument and with the Altazimuth whenever it was possible. In con- 

 sequence of the cloudy weather only twelve observations of the Moon on the 

 meridian were obtained, but on each occasion the clock and instrumental 

 errors were very satisfactorily determined. 



" The Equatorial was mounted in October, but this instrument and the 

 secondary telescope were very little used before the transit of Venus. A 

 few occultations of stars were observed ; but little time could be spared by 

 the observers to ivatch for these phenomena, and consequently only those 

 occultations whose times of occurrence were known received any attention. 



" The Model representing the appearances of the transit of Venus was 

 mounted in November, and Commander Wharton, Lieutenant Hoggan, and 

 myself practised with it. 



" The Expedition was furnished from the Meteorological Office, West- 

 minster, with a very complete set of Meteorological instruments. It was 

 evident at first that to make the necessary observations and entries would 

 occupy more time than the members of the Expedition could afford. The 

 offer, therefore, of a local officer, Police-Sergeant Youlton, to take charge 

 of the Meteorological observations, and to be responsible for the accuracy of 

 the journal, was very welcome. The various instraments were read twice a 

 day. The journal was occasionally examined by Mr. Burton or myself.* 



" The transit of Venus on December 8 was observed by Commander 

 Wharton, Lieutenant Hoggan, and myself. Their reports are appended to 

 my own. 



" The Island of Rodriguez was surveyed by the officers of the Shearwater, 

 under the direction of Commander Wharton. The positions of the secondary 

 stations on Hermitage Islet and at Point Coton depend entirely upon this 

 survey. The difference of longitude between Point Venus and Hermitage 

 Islet was determined by rocket signals in connection with the observations 

 at both places for local time, but preference is given to the difference 

 obtained geodetically. 



" At my request the Colonial Government at Mauritius (to which Rodriguez 



* It is deposited at the Meteorological Office, Westminster. 



