In a long poem variety is indispensable, and he preserved the utmost freedom in some respects. He continually varies the stresses in the line, their number, their weight, and their incidence, letting them fall, when it pleases his ear, on the odd as well as on the even syllables of the line. The pause or caesura he permits to fall at any place in the line, usually towards the middle, but, on occasion, even after the first or ninth syllables. His chief study, it will be found, is to vary the word in relation to the foot, and the sentence in relation to the line. No other metre allows of anything like the variety of blank verse in this regard, and no other metrist makes so splendid a use of its freedom. He never forgets the pattern; yet he never stoops to teach it by the repetition of a monotonous tattoo. Hence there are, perhaps, fewer one-line quotations to be found in the works of Milton than in the works of any other master of blank verse. De Quincey speaks of the "slow planetary wheelings" of Milton's verse, and the metaphor is a happy one; the verse revolves on its axis at every line, but it always has another motion, and is related to a more distant centre. It may well be doubted whether Milton could have given a clear exposition of his own prosody. In the only place where he attempts it he finds the elements of musical delight to consist in "apt numbers, fit quantity of syllables, and the sense variously drawn out from one verse into another." By "apt numbers" he probably meant the skilful handling of stress-variation in relation to the sense. But the last of the three is the essential of Miltonic blank verse. There lies the secret for whoso can divine it. Every well-marked type of blank verse has a natural gait or movement of its own, which it falls into during its ordinary uninspired moods. Tennyson's blank verse, when it is not carefully guarded and varied, drops into a kind of fluent sing-song. Examples may be taken, almost at random, from the _Idylls of the King_. Here is one:-- So all the ways were safe from shore to shore, But in the heart of Arthur pain was lord. The elements of musical delight here are almost barbarous in their simplicity. There is a surfeit of assonance--_all, shore, shore, lord_; _heart, Arthur_; _ways, safe, pain_. The alliteration is without complexity,--a dreary procession of sibilants. Worst of all are the monotonous incidence of the stress, and the unrelieved, undistinguished, crowded poverty of the Saxon monosyllables.