Here’s another from Bartek Drejewicz. Company B of the 2nd U. S. Artillery was not at First Bull Run, but sister companies A (Tidball), D (Arnold), E (Carlisle), G (Greene), & M (Hunt) were all there, so raise your eyes a bit and change the B on her Hardee hat to any one of those and you get the picture.
Bartek is a classically trained artist, and tells me that the prolong in his redleg corporal’s grasp is meant to mimic this piece of classic Greek sculpture, Laocoön and His Sons.
Pliny the Elder attributed the work, said to be an “icon” of human suffering, to Rhodian sculptors Agesander, Athenedoros, and Polydorus. The sculpture now resides in the Vatican, but in Pliny’s time was in the palace of the Emperor Titus. There are several versions of the story, but the long and short of it is that Laocoön was a Trojan priest who was punished by the gods for some transgression.
A prolong is a length of rope used when a gun has to be moved without being limbered, that is, attached to a limber and team of horses. Say, in an emergency. Here’s a sketch showing the prolong where it was normally stored on the carriage, right there on the trail between the handspike and elevating screw:
Learn everything you ever wanted to know about cannons at To the Sound of the Guns.