roil 



FOR 



spnr. 2. Felspar porphyry ; the base of 

 this is red compact felspar, inclosing 1 

 crystals of felspar and quartz. 3. Sceni- 

 tic porphyry ; containing crystals of horn- 

 blende, in addition to the other ingredi- 

 ents. 4. Pitch-stone porphyry ; the base 

 of which is red, green, brown, or black. 

 5. Clay porphyry ; the base of which is 

 indurated clay passing into horn-stone, it 

 is of a reddish colour, and contains crys- 

 tals of quartz and felspar. Horn-sto'ne 

 porphyry is the oldest of the class; and 

 clay porphyry the most recent. The red 

 porphyries are employed in ornamental 

 architecture for columns. 



POUT, a commodious place situated 

 en the sea-coast, or at the mouth of a 

 river, screened from the wind and the 

 f-nterprizes of an enemy, with depth of 

 water sufficient for ships of burden, and 

 where vessels lie by to load and unload. 



Ports are either natural or artificial; 

 the natural are those formed by Provi- 

 dence, and the artificial such as are for- 

 med with moles running into the sea. 

 The city of Constantinople is called 

 " The Port," frtfra its having- one of the 

 finest ports in Europe. All the ports 

 and havens in England are within the 

 jurisdiction of the county; and the Court 

 of Admiralty cannot hold jurisdiction of 

 any thing done in them. 30 Henry VI. 



PORT hales, in a ship, are the holes in 

 the sides of the vessel, through which 

 are put the muz^els of the great guns. 

 These are shut up in storms to prevent 

 the water from driving through them. 

 The English, Dutch, and French ships, 

 have the valves, or casements, fastened 

 at the top of the port holes, and the 

 Spanish vessels aside of them. 



PORTAL, in architecture, a little gate 

 where there are Uvo gates of a different 

 bigness; also a little square corner of a 

 room cut of!' from the rest by the wain- 

 scot, and forming a short passage into 

 'lu HK'in. The s;tme name is also some- 

 times ;ivcn to a kind of arch of joiners' 

 work before a door. 



POHTCULUCE, in fortification, is an 

 assemblage of several large pieces of 

 wood, joined across one another like a 

 harrow, and each pointed with iron at 

 the bottom. They are sometimes hung 

 , over the gateway of old fortified towns, 

 ready to let clown in case of surprise, 

 when the gates could not be shut. 



PORTER, a kind of malt liquor, which 

 differs from ale and pale beer in its be- 

 ing made with high-dried malt. 



PORTGREVE, or PORTGRAVF,, anci- 

 ently the principal magistrate in ports 

 and other maritime towns. The word is 



formed from the Saxon " port," and 

 "geref," a governor. It is sometimes 

 also written " portreve." It is said by 

 Camden, that the chief magistrate of 

 London was anciently called port-greve, 

 which was exchanged by Richard I. for 

 two bailiffs: and these again gave place, 

 in the reign of King John, to a mayor, 

 who was an annually elected magistrate. 



PORTICO, in architecture, a kind of 

 gallery on the ground, supported by co- 

 lumns, where people walk under covert. 



PORTLAND-STONE, is a dull whitish 

 species of stone, much used in buildings; 

 it is composed of a coarse grit, cemented 

 together by an earthy spar: it will not 

 strike fire with steel, but makes a vio- 

 lent effervescence with nitric acid. 



PORTLAND vase, a celebrated funeral 

 vase, which was long in the possession of 

 the Baberini family ; but which was some 

 \ears since purchased for 1000 guineas 

 by the Duke of Portland, from whom it 

 has derived its present name. Its height 

 is about ten inches, and its diameter, 

 whe.re broadest, six. There are a variety 

 of figures upon it, of most exquisite 

 workmanship, in has relief, of white 

 opaque glass, raised on a ground of deep 

 blue glass, which appears black, except 

 when held against the light. It appears 

 to have been the work of many years, and 

 there are antiquarians who date its pro- 

 duction several centuries before the 

 Christian era; since, as has been said, 

 sculpture was declining in excellence in 

 the time of Alexander the Great. Re- 

 specting the purpose of this vase, and 

 what the figures on it were meant to 

 represent, there have been a variety of 

 conjectures. AVe shall, therefore, give 

 a short account of the several figures, 

 without noticing any of the theories or 

 conjectures that have been made about 

 them. In one compartment three ex- 

 quisite figures are placed OH a ruined 

 column, the capital of which is fallen, 

 and lies at their feet among other dis- 

 jointed stones: they sit under a tree on 

 loose piles of stone. The middle figure 

 is a female, in a reclining and dying at- 

 titude, with an inverted torch in her left 

 hand, the elbow of which supports her 

 as she sinks, while the right hand is 

 raised and thrown over her drooping 

 head. The figure on her right hand is 

 a man, and that on the left a woman, both 

 supporting themselves on their arms, and 

 apparently thinking intensely. Their 

 backs are to the dying figure, and their 

 faces are turned to her, but without an 

 attempt to assist her. On another com- 

 partment of the va*e is a figure coming 



