To attack the left of General McClellan, promised small results.

It had been tried and had failed; his right alone remained.

It was possible, certainly, that he would mass his army, and, crushing Magruder, march into Richmond; but it was not probable that he would make the attempt.

The Federal commander was known to be a soldier disposed to caution rather than audacity.

The small amount of force under General Magruder was a secret which he could not be expected to know.