NAVIGATION. 61 



" Pilots are usually to be found some distance 

 from the entrance of the Tagus ; their boats are 

 to be distinguished from others by a blue flag 

 hoisted at the yard-arm of their lateen sails. 



" LEADING MARKS. Santa Martha Fort, to 

 the southward of Cascaes, is white, and of a 

 triangular form to the eastward, with a low 

 battery extending to the northward ; Guia light- 

 house in one with the bastion of this fort, 



N.W.iW., leads through the North Channel. 

 ***** 



" Fort San Julian is an extensive fortification, 

 erected on a high steep point on the north-west 

 side of the entrance to the Tagus. A ledge of 

 rocks, with 3^ fathoms, extends a short distance 

 to the south-eastward of the fort. 



" Bugio Fort stands upon the highest part of 

 the South Cachopo, about two-thirds of a mile 

 from Medao Point, the south-east point of the 

 mouth of the Tagus ; the fort is of a circular 

 form, and the sand round it is dry at low water. 



" The Paps are very difficult to be distinguished, 

 particularly on the bearing used for the South 



