PETERSFIELD, NOV. 27. Letters have been received from Commander Butterfield, of the Fantome, dated Saint Helena, October the 7th, from which we learn that the Fantome sailed from St. Helena on the 1st for the Cape; on the 3rd she chased and captured the Portuguese brigantine Conceira de Maria, with 475 slaves on board from Mozambique to Pernambuco. The slaver, being short of provisions and water, the Fantome took her in tow and returned to St. Helena, where she arrived on the 5th. Since writing the above we have learnt with pleasure the indefatigable commander has been promoted to the rank of post captain.