INDISTINCTNESS OF IDEAS. 191 



blow, the waves may rage ; but this small creature coutrols their fury, 

 and stops a vessel, when chains and anchors would not hold it : and 

 this it does, not by hard labor, but merely by adhering to it. Alas, 

 for human vanity ! when the turreted ships which man has built, that 

 he may fight from castle-walls, at sea as well as at land, are held cap- 

 tive and motionless by a fish a foot and a half long ! Such a fish is 

 said to have stopped the admiral's ship at the battle of Actium, and 

 compelled Antony to go into another. And in our own memory, one of 

 these animals held fast the ship of Caius, the emperor, when he was sail- 

 ing from Astura to Antium. The stopping of this ship, when all the 

 rest of the fleet went on, caused surprise ; but this did not last long, 

 for some of the men jumped into the water to look for the fish, and 

 found it sticking to the rudder; they showed it to Caius, who was in- 

 dignant that this animal should interpose its prohibition to his prog- 

 ress, when impelled by four hundred rowers. It was like a slug ; and 

 had no power, after it was taken into the ship." 



A very little advance in the power of thinking clearly on the force 

 which it exerted in pulling, would have enabled the Romans to see 

 that the ship and its rowers must pull the adhering fish by the hold 

 the oars had upon the water ; and that, except the fish had a hold 

 equally strong on some external body, it could not resist this force. 



3. Indistinctness of Ideas shown in Architecture. — Perhaps it may 

 serve to illustrate still further the extent to which, under the Roman 

 empire, men's notions of mechanical relations became faint, wavered, 

 and disappeared, if we observe the change which took place in archi- 

 tecture. All architecture, to possess genuine beauty, must be mechan- 

 ically consistent. The decorative members must represent a structure 

 which has in it a principle of support and stability. Thus the Grecian 

 colonnade was a straight horizontal beam, resting on vertical props ; 

 and the pediment imitated a frame like a roof, where oppositely 

 inclined beams support each other. These forms of building were, 

 therefore, proper models of art, because they implied supporting forces. 

 But to be content with colonnades and pediments, which, though they 

 imitated the forms of the Grecian ones, were destitute of their mechan- 

 ical truth, belonged to the decline of art ; and showed that men had 

 lost the idea of force, and retained only that of shape. Yet this was 

 what the architects of the Roman empire did. Under their hands, the 

 pediment was severed at its vertex, and divided into separate halves, 

 so that it was no longer a mechanical possibility. The entablature 

 no longer lay straight from pillar to pillar, but, projecting over each 



