Across this isthmus, Colonel Prescott conducted the detachment undiscovered, and up the ascent of Bunker's Hill. This commences at the Neck, and slopes up for about three hundred yards to its summit, which is about one hundred and twelve feet high. It then declines toward the south, and is connected by a ridge with Breed's Hill, about sixty or seventy feet high. The crests of the two hills are about seven hundred yards apart. On attaining the heights, a question rose which of the two they should proceed to fortify. Bunker's Hill was specified in the written orders given to Colonel Prescott by General Ward, but Breed's Hill was much nearer to Boston, and had a better command of the town and shipping. Bunker's Hill, also, being on the upper and narrower part of the peninsula, was itself commanded by the same ship which raked the Neck. Putnam was clear for commencing at Breed's Hill, and making the principal work there, while a minor work might be thrown up at Bunker's Hill, as a protection in the rear, and a rallying point, in case of being driven out of the main work. Others concurred with this opinion, yet there was a hesitation in deviating from the letter of their orders. At length Colonel Gridley became impatient; the night was waning; delay might prostrate the whole enterprise. Breed's Hill was then determined on. Gridley marked out the lines for the fortifications; the men stacked their guns; threw off their packs; seized their trenching tools, and set to work with great spirit; but so much time had been wasted in discussion, that it was midnight before they struck the first spade into the ground. Prescott, who felt the responsibility of his charge, almost despaired of carrying on these operations undiscovered. A party was sent out by him silently to patrol the shore at the foot of the heights, and watch for any movement of the enemy. Not willing to trust entirely to the vigilance of others, he twice went down during the night to the water's edge; reconnoitering every thing scrupulously, and noting every sight and sound. It was a warm, still, summer's night; the stars shone brightly, but every thing was quiet. Boston was buried in sleep. The sentry's cry of "All's well" could be heard distinctly from its shores, together with the drowsy calling of the watch on board of the ships of war, and then all would relapse into silence. Satisfied that the enemy were perfectly unconscious of what was going on upon the hill, he returned to the works, and a little before daybreak called in the patrolling party.