Sentence:  This example is much richer, yet no less elegant, than the other; the <WSD>volute</WSD>, instead of a single spiral, is formed by three; the sculptured echinus beneath is surmounted by a guilloched moulding, and separated from the shaft by a neck ... 
Meaning of the word marked with <WSD> tags:  The characteristic spiral curve on an Ionic capital, widely copied in other styles and in neoclassical architecture.