224 Mr Barlow on the apparent acceleration 



rison at Cerigo, who came on board the following morning, we 

 learned that no earthquake had been felt in that island, though 

 it forms such a connecting link between the above places, and 

 though that which we had experienced must have been of very 

 considerable violence, to be transmitted through a mass of wa- 

 ter of at least 500 fathoms in depth. Slight shocks, I imagine, 

 are seldom communicated, even through shallow water ; for it 

 has twice happened to me in Smyrna to have been wakened at 

 night by smart vibrations of the bed, when nothing was felt on 

 board, though the ship was at anchor only one-third of a mile 

 from the house in which I slept, and though officers and sen- 

 tinels were upon deck, by all of whom such an occurrence 

 could not have been unobserved. 



Though very unlikely to have been connected with the 

 earthquake which was felt on board the Salsette, it may not 

 be uninteresting to mention that, on the preceding evening, 

 between 9 and 10 o'clock, several meteors, of different degrees 

 of brilliancy, were seen ; and that one of them, which emitted 

 a long train of sparks, passed so near the ship that I heard the 

 whizzing sound of its flight through the air, and, immediately 

 after its disappearance, the fall of a ponderous body into the 

 water. I am, &c. F. B. 



Art. V. — Conjectures as to the Cause of the high degree of 

 apparent acceleration in the Rates of the Chronometers ob- 

 served by Mr Fisher, and reported by him in the Phil. 

 Trans. By Peter Barlow, Esq. F. R. S. Mem. Imp. 

 Acad. Petrop. Communicated by the Author. 



When we consider the long practice which has now been had 

 in the use of chronometers on ship-board, without any very 

 remarkable change having been observed between the land 

 and sea rates, although there can be no doubt some small 

 change does take place ; and when we combine with this previ- 

 ous practice, the valuable observations of Captain Parry in his 

 late voyages, we cannot do otherwise than consider the results 

 obtained by Mr Fisher at Spitzbergen as anomalous, and as 



