SUMATEAN ISLANDS. 



93 



to tte west the oceanic bed sinks rapidly, and within GO miles of the islands the 

 sounding line reveals depths of over 2,500 fathoms. 



Beginning- in the north-west with the island of Babi, the chain terminates in 

 the south-east with Engano,* over 720 miles distant. The isolated islet of Christ- 

 mas, 300 miles farther on, might also perhaps be regarded as belonging to the 



same system, lying as it does in a line with its axis, but this point is rendered 

 somewhat doubtful by the distance and the great depths of the intervening waters. 

 Excluding this rock, the western islands, which beyond doubt depend geographi- 

 cally and geologically on Sumatra, have a total superficial area of about 6,000 



* Telanjang of the Malays, Taigoeka of the natives, and probably the Engano, or ' ' Deception 

 Island," of the Spaniards. 



