LONGITUDE OF SUPPLY BAY. 459 



All the stars, except Trianguli Australis, are on the North side of the 

 Zenith. It seems not improbable that the inferred colatitude is a second or 

 two too great. 



The results are not so accordant as might have been expected with such an 

 instrument; possibly the discordances are due to the employment of two 

 microscopes only. 



ON THE LONGITUDE OF SUPPLY BAY. 



As previously arranged, on the evening of November 16 Lieut. Goodridge 

 ascended to the summit of Mussel Island, off the entrance of Observatory Bay, 

 and exploded a quantity of gunpowder at intervals of ten mimites, a pre- 

 paratory rocket being sent up at 8.30 p.m. The understanding was that 

 similar signals should be made by the American observers five minutes after 

 each of Lieut. Goodridge' s signals. The signals from Mussel Island, four in 

 number, were all seen at Observatory Bay, and from a repeating station at 

 Supply Bay ; the first three only at Molloy Point. The Molloy Point signals 

 were not seen at Observatory Bay, but were all seen at Supply Bay. The 

 powder flashes being invisible from Supply Bay observatory, Messrs. Coke 

 and Baynes ascended a hill about half a mile distant, whence all the signals 

 were visible. Having their fowling pieces on full cock, they discharged them 

 immediately they perceived the signals, and estimated at once, independently, 

 the loss of time incurred by this repetition. Lieut. Corbet registered the 

 instant of hearing the gunshots. The distance of the repeating station was 

 afterwards measured, and Messrs. Coke and Baynes made a number of 

 experiments to determine the value of their estimates of the loss of time in 

 repeating. 



The following are the times recorded and inferred difference of longitude 

 between Supply Bay and Observatory Bay, and between Supply Bay and 

 Molloy Point. Professor S. Newcomb kindly supplies the local mean times 

 observed at Molloy Point. 



