This is from the report Hemingway filed in 1923 about his first running of the bulls in Pamplona, when he and his wife (Herself) were the only English-speakers in town.
... It was really a double wooden fence, making a long entryway from the main street of the town to the bull ring itself. It made a runway about two hundred and fifty yards long. People were jammed solid on each side of it. Looking up it toward the main street.
Then far away there was a dull report.
"They're off," everybody shouted.
"What is it?" I asked a man next to me who was leaning far out over the concrete rail.
"The bulls! They have released them from the corrals on the far side of the city. They are racing through the city."
"Whew," said Herself. "What do they do that for?"
Then down the narrow fenced-in runway came a crowd of men and boys running. Running as hard as they could go. The gate feeding them into the bull ring was opened and they all ran pell-mell under the entrance levels into the ring. Then there came another crowd. Running even harder. Straight up the long pen from the town.
"Where are the bulls?" asked Herself.
Then they came in sight. Eight bulls galloping along, full tilt, heavy set, black, glistening, sinister, their horns bare, tossing their heads. And running with them three steers with bells on their necks. They ran in a solid mass, and ahead of them sprinted, tore, ran and bolted the rear guard of the men and boys of Pamplona who had allowed themselves to be chased through the streets for a morning's pleasure.
A boy in his blue shirt, red sash, white canvas shoes with the inevitable leather wine bottle hung from his shoulders, stumbled as he sprinted down the straightaway. The first bull lowered his head and made a jerky, sideways toss. The boy crashed up against the fence and lay there limp, the herd running solidly together passed him up. The crowd roared.
Everybody made a dash for the inside of the ring, and we got into a box just in time to see the bulls come into the ring filled with men. The men ran in a panic to each side. The bulls, bunched solidly together, ran straight with the trained steers across the ring and into the entrance that led to the pens.
That was the entry. Every morning during the bull fighting festival of San Fermin at Pamplona the bulls that are to fight in the afternoon are released from their corrals at six o'clock in the morning and race through the main street of the town for a mile and a half to the pen. The men who run ahead of them do it for the fun of the thing....