The substitution of timber for iron demands a closer placing of the pillars.  They are consequently but sixteen feet apart “in the row,” the spans being correspondingly more contracted.  This has the compensating advantage, aesthetically speaking, of offering more surface for decorative effect, and the opportunity has been fairly availed of.  The coloring of the roof, tie-rods and piers expands over the turmoil below the cooling calm of blue and silver.  To this the eye, distracted with the dance of bobbins and the whirl of shafts, can turn for relief, even as Tubal Cain, pausing to wipe his brow, lifted his wearied gaze to the welkin.

Machinery Hall has illustrated, from its earliest days, the process of development by gemmation.  Southward, toward the sun, it has shot forth several lusty sprouts.  The hydraulic avenue which we have mentioned covers an acre, being two hundred and eight by two hundred and ten feet.  Cheek by jowl with water is its neighbor fire, safe behind bars in the boiler-house of the big engine; and next branches out, over another acre and more, or forty-eight thousand square feet, the domain of shoes and leather under a roof of its own.

Including galleries and the leather, fire and water suburbs, this structure affords more than fifteen acres of space.  Over that area it rose like an exhalation in the spring and early summer of 1875.  At the close of winter it existed only in the drawings of Messrs. Pettit & Wilson.  Under the hands of Mr. Philip Quigley it was ready to shelter a great Fourth of July demonstration.  This matches the rapidity of growth of its neighbor before described.  The Main Building, designed by the same firm, had its foundations laid by Mr. R.J.  Dobbins, contractor, in the fall of 1874, but nothing further could be done till the following spring.  The first column was erected, an iron Maypole, on the first day of the month of flowers, and the last on the 27th of October.  Three weeks later the last girder was in place.  All had been done with the precision of machinery, no pillar varying half an inch from its line.  Machinery, indeed, rolled the quadrant-shaped sections of each column and riveted their flanges together with hydraulic hammers; great steam-derricks dropped each on its appointed seat; and the main tasks of manual labor in either building were painting, glazing, floor-laying and erecting the ground-wall of masonry, from five to seven feet high, that fills in the outer columns all round to a level with the heads of theorists who, holding that la propriete c’est le vol, assert the propriety of theft.