...busy at this work since three o'clock. The line of bluffs masked all view of the river; but, in fact, General Buell's Army of the Ohio was also now arriving from Savannah, on the opposite bank, below Pittsburg Landing , and Ammen's brigade, of Nelson's advance division, had been thrown across and placed in support of Webster's battery, at five o'clock. Generals Buell and Nelson were both present on the field. Behi...