408 PHILOSOPHICAL TRANSACTIONS. [aNNO I767. 



in the comet of l665, of which he finds the quantity of matter to be to that in 

 the sun, as ] to 1510724, and its density about 34- times that of the earth. 

 And the density of the comet of l682, to the density of the earth, is in like 

 manner found to be as 5 to 1 1 nearly. 



XVJI. Some Attempts to Ascertain the Utmost Extent of the Knowledge of the 

 Ancients in the East Indies.* By Mr. John Caverhill. p. 155. 



It may be proper first to observe, that Cattigara was the name of a port situ- 

 ated somewhere beyond the Aurea Chersonesus or Malacca ; and that the ancients 

 had never sailed farther than Cattigara: for contiguous to it was a terra incog- 

 nita. But at what distance the Aurea Chersonesus was from Cattigara, Ptolemy 

 himself was ignorant; for he says, that Marinus, who is quoted by him on this 

 occasion, had not marked the number of the stadia. By a vague calculation on 

 the report of seamen, Ptolemy makes Cattigara 17-5- degrees of longitude from 

 Malacca, whereas they are nearly on the same meridian. For several reasons, 

 Mr. C. concludes, it is extremely probable that Cattigara stood somewhere on 

 the north-east coast of the bay of Siam, and probably the same as the port Pon- 

 teamas; also that the modern city Cambodia is the ancient metropolis Sinae. It 

 appears too that the ancients sailed to, and were acquainted with the island of 

 Java, and they made mention of the Manillas. Notwithstanding Ptolemy has 

 mentioned the Philippines, yet we do not imagine that any of the persons from 

 whom he acquired his information had ever been there: but that they had heard 

 of these places at Java, to which they might easily have sailed, either from the 

 Javanese themselves, or from the inhabitants of the circumjacent islands, who 

 resorted to Java for the same advantages of commerce which they themselves 

 came in pursuit of. However, though they must almost necessarily have been 

 acquainted with Sumatra, yet it is evident they had never sailed quite round it ; 

 for if they had, they would certainly not have mentioned Ceylon as the largest 

 island in the ocean. Hence it would appear that they only knew part of Su- 

 matra and Java; and either conjectured these were islands, or depended on some 

 informations they might probably have received from the inhabitants of these 

 places, relative to this particular. 



So that here we may venture to fix the limits of Ptolemy's knowledge; for as 

 these islands at that time were but a late discovery, they were very imperfectly 

 known; and unfortunately the geographers who lived after him were all so pre- 

 possessed with his superior abilities, that they imagined his accuracy would bear 

 no correction, and that he had exhausted the subject. For no other author 



* On this subject a more extended treatise wns written by the late celebrated liistorian Dr. 

 Robertioiij of Edinburgh. See also Dr. Vincent's Periplus of the Erythraean Sea. 



