Scores of "trypod" and "Star" drills, whole battalions of deafening machines run by compressed air brought from miles away, are pounding and grinding and jamming holes in the living rock. After them will presently come nonchalantly strolling along gangs of the ubiquitous black "powder-men" and carelessly throw down boxes of dynamite and pound the drill-holes full thereof and tamp them down ready to "blow" at 11:30 and 5:30 when the workmen are out of range,--those mighty explosions that twelve times a week set the porch chairs of every I.C.C. house on the Isthmus to rocking, and are heard far out at sea. Anywhere near the drills is such a roaring and jangling that I must bellow at the top of my voice to be heard at all. The entire gamut of sound-waves surrounds and enfolds me, and with it all the powerful Atlantic breeze sweeps deafeningly through the channel. Down in the bottom of the canal if one step behind anything that shuts off the breeze it is tropically hot; yet up on the edge of the chasm above, the trees are always nodding and bowing before the ceaseless wind from off the Caribbean. Scores of "switcheros" drowse under their sheet-iron wigwams, erected not so much as protection from the sun, for the drowsers are mostly negroes and immune to that, as from young rocks that the dynamite blasts frequently toss a quarter-mile. Then over it all hang heavy clouds of soft-coal dust from trains and shovels, shifting down upon the black, white and mixed, and the enumerator alike; a dirty, noisy, perilous, enjoyable job. Everywhere are gangs of men, sometimes two or three gangs working together at the same task. Shovel gangs, track gangs, surfacing gangs, dynamite gangs, gangs doing everything imaginable with shovel and pick and crowbar, gangs down on the floor of the canal, gangs far up the steep walls of cut rock, gangs stretching away in either direction till those far off look like upright bands of the leaf-cutting ants of Panamanian jungles; gangs nearly all, whatever their nationality, in the blue shirts and khaki trousers of the Zone commissary, giving a peculiar color scheme to all the scene.