There was a slight labor, now, and something of the same heave and pitch which comes in the gait of a common horse; also, when he put Satan up the first slope beyond Ganton he noted a faltering, a deeper lowering of the head.

When his hoofs struck a loose rock he no longer had the easy recoil of the morning.

He staggered like a graceful yacht chopped by a cross-current.

Now down the slope, now back to the roar of the Asper once more, for there the going was most level, but always the strides were shortening, shortening, and the head of the stallion nodded at his work.
All that was seen by Mark Retherton through his glasses, though they were almost close enough now to see details through the naked eye.

He turned in the saddle to the posse, grim faces, sweat and dust clotted in their moustaches, their faces drawn and gray with streaks over the nose and under the eyes where perspiration ran.