CLVII1 



tdrografico deU" Lmmiragliato inglese le variazioni della Bussola rilevate 



nel Mediterrauco, nel mar Nero c nel mar Rosso, offre genlilmcnte in 

 dono all' \ccadcmia una copia manoscritla della seguente Tavola contc- 

 nente le variazioni sovra mentovate. 



NOTICE TO MARINERS. 



N." 27. 



Mediterranean, Black, and Red Seas variation of the compass 1857. 



« The following information respecting the variation of the compass 

 in the Mediterranean, Black, and Red Seas is made public in order to 

 apprize mariners of the gradual decrease in the variation , which in many 

 places , since the commencement of the present century, has amounted 

 to more than half a Point. 



The average rate of annual decrease at the present lime appears to 

 be about 3' at the western limits of the Mediterranean, 5' in the central 

 portion, 6' in the eastern limits and the Black Sea, and about 7' in 

 the Red Sea : 



Spain, France, and Italy. 



Gibraltar 20 W 



Cape de Gat 19 » 



Cape Antonio and Tarragona . . 18 j » 



Barcelona and Cape Creux .... 18 » 



Marseille and Toulon 17 » 



Genoa : ;> i W 



Leghorn i5 » 



Naples i3^° » 



Cape Spartivento 12 j » 



Gulf of Taranto 12 » 



Principal Islands. 



Port Mahon ( Minorca ) 17 



Corsica and Sardinia i5 \ 



Pantellaria, and West / 



14 



coasts of Sicily \ 



Malta i3*° 



East coasts of Sicily 13 j 



Ionian Islands 10 3 



Cape Spartel 20 



Cape Ferrat 18 



Majors 17 \ 



Cape Scrrat and Galila Island .. i5{ 

 Cape Bon and Skerki Shoals .. 1 4 s 



North coast of Africa. 



w 



■3 



Tripoli 



Ben Ghazi u" " 



Bombah 9j " 



Alexandria 7 « » 



