The troops detached for this service, amounted to about one thousand men. They were ordered to take provisions but for a single day. In the early part of the evening of the 16th, they were mustered on Cambridge common, near the colleges. They were commended to the protection and guidance of Almighty God, in a prayer by President Langdon; after which, led by the valiant Prescott, attired in a _calico frock_, and himself preceded by two sergeants with dark lanterns, and accompanied by Colonel Gridley and Judge Winthrop of Cambridge, they took their destined path. Having reached the ground, a question arose which of the two hills was intended as Bunker's hill. The northern eminence was more generally spoken of under that name, while the southern, commonly called Breed's hill, was evidently the one best fitted for the purpose. After long deliberation, it was decided to construct the principal work on Breed's hill, and to erect an additional and subsidiary one on Bunker's hill. Accordingly, Captain Gridley proceeded to lay out the principal work. Midnight arrived, however, before a spade entered the ground; there remained therefore less than four hours before day-light, when the operations would, of course, be seen by the British. The men, however, now began, and they _worked_. [Illustration: President Langdon at Prayer.] Meanwhile, a strong guard, under Captain Manners, was stationed on the Charlestown shore, to watch the enemy. The day had been fair, and it was a clear, star-light night. Colonel Prescott, accompanied by Major Brooks, went down twice to the shore to reconnoitre, and distinctly heard the British sentries relieving guard, and uttering, as they walked their rounds, the customary, but, in this instance deceptive, cry, "All's well!"[32] The night, on the part of the patriot band, was one of sleepless vigilance and incessant toil. Shovels, pickaxes, and spades, were in incessant motion; and, by four o'clock in the morning, they had thrown up a redoubt, eight rods square and four feet high. At this time, the captain of a British ship, called the _Lively_, discovered the work, and opened a fire upon it. The alarm was given to the British in Boston, and to the men-of-war in the river, and a heavy cannonade was commenced. The fire from a battery of six guns, on Copp's hill, proved most annoying; but the Americans, regardless of bombs and balls, continued their labors with unshaken constancy. The first martyr who had the honor of shedding his blood, on that ever-memorable hill, was a private soldier by the name of _Asa Pollard_, of Billerica, and the shot which killed him was the only one which took fatal effect during the forenoon. [Illustration: Death of Pollard.]