five o’clock
At four o'clock three companies of infantry came and took up their positions along the pavements , while a battalion occupied the Boulevard Arago in case of a surprise . Municipal guards cantered up and down between the lines ; a whole staff of police-magistrates , officers and functionaries , brought together for the occasion , moved about among the troops . The guillotine was set up in silence , in the middle of the square formed by the boulevard and the street ; and the sinister sound of hammering was heard . But , at five o'clock , the crowd gathered , notwithstanding the rain , and people began to sing . They shouted for the footlights , called for the curtain to rise , were exasperated to see that , at the distance at which the barriers had been fixed , they could hardly distinguish the uprights of the guillotine . Several carriages drove up , bringing official persons dressed in black . There were cheers and hoots , whereupon a troop of mounted municipal guards scattered the groups and cleared the space to a distance of three hundred yards from the square .