Classic Poetry Series James Clerk Maxwell - poems - Publication Date: 2004 Publisher: PoemHunter.Com - The World's Poetry Archive A Problem in Dynamics An inextensible heavy chain Lies on a smooth horizontal plane, An impulsive force is applied at A, Required the initial motion of K. Let ds be the infinitesimal link, Of which for the present we’ve only to think; Let T be the tension, and T + dT The same for the end that is nearest to B. Let a be put, by a common convention, For the angle at M ’twixt OX and the tension; Let Vt and Vn be ds’s velocities, Of which Vt along and Vn across it is; Then Vn/Vt the tangent will equal, Of the angle of starting worked out in the sequel. In working the problem the first thing of course is To equate the impressed and effectual forces. K is tugged by two tensions, whose difference dT Must equal the element's mass into Vt. Vn must be due to the force perpendicular To ds’s direction, which shows the particular Advantage of using da to serve at your Pleasure to estimate ds’s curvature. For Vn into mass of a unit of chain Must equal the curvature into the strain. Thus managing cause and effect to discriminate, The student must fruitlessly try to eliminate, And painfully learn, that in order to do it, he Must find the Equation of Continuity. The reason is this, that the tough little element, Which the force of impulsion to beat to a jelly meant, Was endowed with a property incomprehensible, And was "given," in the language of Shop, "inexten-sible." It therefore with such pertinacity odd defied The force which the length of the chain should have modified, That its stubborn example may possibly yet recall These overgrown rhymes to their prosody metrical. The condition is got by resolving again, According to axes assumed in the plane. If then you reduce to the tangent and normal, You will find the equation more neat tho’ less formal. The condition thus found after these preparations, When duly combined with the former equations, Will give you another, in which differentials (When the chain forms a circle), become in essentials No harder than those that we easily solve In the time a T totum would take to revolve. Now joyfully leaving ds to itself, a- Ttend to the values of T and of a. www.PoemHunter.com - The World's Poetry Archive 2 The chain undergoes a distorting convulsion, Produced first at A by the force of impulsion. In magnitude R, in direction tangential, Equating this R to the form exponential, Obtained for the tension when a is zero, It will measure the tug, such a tug as the "hero Plume-waving" experienced, tied to the chariot. But when dragged by the heels his grim head could not carry aught, So give a its due at the end of the chain, And the tension ought there to be zero again. From these two conditions we get three equations, Which serve to determine the proper relations Between the first impulse and each coefficient In the form for the tension, and this is sufficient To work out the problem, and then, if you choose, You may turn it and twist it the Dons to amuse. James Clerk Maxwell www.PoemHunter.com - The World's Poetry Archive 3 A Student's Evening Hymn I. Now no more the slanting rays With the mountain summits dally, Now no more in crimson blaze Evening’s fleecy cloudless rally, Soon shall Night front off the valley Sweep that bright yet earthly haze, And the stars most musically Move in endless rounds of praise. II. While the world is growing dim, And the Sun is slow descending Past the far horizon’s rim, Earth's low sky to heaven extending, Let my feeble earth-notes, blending With the songs of cherubim, Through the same expanse ascending, Thus renew my evening hymn. III. Thou that fill’st our waiting eyes With the food of contemplation, Setting in thy darkened skies Signs of infinite creation, Grant to nightly meditation What the toilsome day denies— Teach me in this earthly station Heavenly Truth to realise. IV. Give me wisdom so to use These brief hours of thoughtful leisure, That I may no instant lose In mere meditative pleasure, But with strictest justice measure All the ends my life pursues, Lies to crush and truths to treasure, Wrong to shun and Right to choose. V. Then, when unexpected Sleep, O’er my long-closed eyelids stealing, www.PoemHunter.com - The World's Poetry Archive 4 Opens up that lower deep Where Existence has no feeling, May sweet Calm, my languor healing, Lend note strength at dawn to reap All that Shadows, world-concealing, For the bold enquirer keep. VI. Through the creatures Thou hast made Show the brightness of Thy glory, Be eternal Truth displayed In their substance transitory, Till green Earth and Ocean hoary, Massy rock and tender blade Tell the same unending story— "We are Truth in Form arrayed." VII. When to study I retire, And from books of ancient sages Glean fresh sparks of buried fire Lurking in their ample pages— While the task my mind engages Let old words new truths inspire-— Truths that to all after-ages Prompt the Thoughts that never tire. VIII. Yet if, led by shadows fair I have uttered words of folly, Let the kind absorbing air Stifle every sound unholy. So when Saints with Angels lowly Join in heaven’s unceasing prayer, Mine as certainly, though slowly, May ascend and mingle there. IX. Teach me so Thy works to read That my faith,—new strength accruing,— May from world to world proceed, Wisdom's fruitful search pursuing; Till, thy truth my mind imbuing, I proclaim the Eternal Creed, www.PoemHunter.com - The World's Poetry Archive 5 Oft the glorious theme renewing God our Lord is God indeed. X. Give me love aright to trace Thine to everything created, Preaching to a ransomed race By Thy mercy renovated, Till with all thy fulness sated I behold thee face to face And with Ardour unabated Sing the glories of thy grace. James Clerk Maxwell www.PoemHunter.com - The World's Poetry Archive 6 A Vision of a Wrangler, of a University, of Pedantry, and of Philosophy Deep St. Mary's bell had sounded, And the twelve notes gently rounded Endless chimneys that surrounded My abode in Trinity. (Letter G, Old Court, South Attics), I shut up my mathematics, That confounded hydrostatics -- Sink it in the deepest sea! In the grate the flickering embers Served to show how dull November’s Fogs had stamped my torpid members, Like a plucked and skinny goose. And as I prepared for bed, I Asked myself with voice unsteady, If of all the stuff I read, I Ever made the slightest use. Late to bed and early rising, Ever luxury despising, Ever training, never "sizing," I have suffered with the rest. Yellow cheek and forehead ruddy, Memory confused and muddy, These are the effects of study Of a subject so unblest. Look beyond, and see the wrangler, Now become a College dangler, Court some spiritual angler, Nibbling at his golden bait. Hear him silence restive Reason, Her advice is out of season, While her lord is plotting treason Gainst himself, and Church or State. See him next with place and pension, And the very best intention Of upholding that Convention Under which his fortunes rose. Every scruple is rejected, With his cherished schemes connected, "Higher Powers may be neglected -- His result no further goes." Much he lauds the education Which has raised to lofty station, Men, whose powers of calculation Calculation’s self defied. How the learned fool would wonder Were he now to see his blunder, When he put his reason under www.PoemHunter.com - The World's Poetry Archive 7 The control of worldly Pride. Thus I muttered, very seedy, Husky was my throat, and reedy; And no wonder, for indeed I Now had caught a dreadful cold. Thickest fog had settled slowly Round the candle, burning lowly, Round the fire, where melancholy Traced retreating hills of gold. Still those papers lay before me -- Problems made express to bore me, When a silent change came o’er me, In my hard uneasy chair. Fire and fog, and candle faded, Spectral forms the room invaded, Little creatures, that paraded On the problems lying there. Fathers there, of every college, Led the glorious ranks of knowledge, Men, whose virtues all acknowledge Levied the proctorial fines; There the modest Moderators, Set apart as arbitrators ’Twixt contending calculators, Scrutinised the trembling lines. All the costly apparatus, That is meant to elevate us To the intellectual status Necessary for degrees -- College tutors -- private coaches -- Line the Senate-house approaches. If our Alma Mater dote, she’s Taken care of well by these. Much I doubted if the vision Were the simple repetition Of the statements of Commission, Strangely jumbled, oddly placed. When an awful form ascended, And with cruel words defended Those abuses that offended My unsanctioned private taste. Angular in form and feature, Unlike any earthly creature, She had properties to meet your Eye whatever you might view. Hair of pens and skin of paper; www.PoemHunter.com - The World's Poetry Archive 8 Breath, not breath but chemic vapour; Dress, -- such dress as College Draper Fashions with precision due. Eyes of glass, with optic axes Twisting rays of light as flax is Twisted, while the Parallax is Made to show the real size.