They were not assaulting; they were watching for chances.
"Keep your men together, Sergeant," said Thurstane.

"I must get those Mexicans to work." He trotted deliberately to the other end of the train, ordering each driver as he passed to move up abreast of the leading wagon, directing the first to the right, the second to the left, and so on.

The result of this movement would of course be to bring the train into a compact mass and render it more defensible.

The Indians no sooner perceived the advance than they divined its object and made an effort to prevent it.

Thurstane had scarcely reached the centre of the line of vehicles when a score or so of yelling horsemen made a caracoling, prancing charge upon him, accompanying it with a flight of arrows.