"What!" exclaimed Ben. "Did the explosion destroy three hundred houses!"

"Yes, sir, my father was in Leyden at the time. He says it was terrible. The explosion occurred just at noon and it was like a volcano. All this part of the town was on fire in an instant, buildings tumbling down and men, women, and children groaning under the ruins. The king himself came to the city and acted nobly, Father says, staying out in the streets all night, encouraging the survivors in their efforts to arrest the fire and rescue as many as possible from under the heaps of stone and rubbish. Through his means a collection for the benefit of the sufferers was raised throughout the kingdom, besides a hundred thousand guilders paid out of the treasury. Father was only nineteen years old then. It was in 1807, I believe, but he remembers it perfectly. A friend of his, Professor Luzac, was among the killed. They have a tablet erected to his memory, in Saint Peter's Church, farther on--the queerest thing you ever saw, with an image of the professor carved upon it, representing him just as he looked when he was found after the explosion."

"What a strange idea! Isn't Boerhaave's monument in Saint Peter's also?"

"I cannot remember. Perhaps Peter knows."

The captain delighted Ben by saying that the monument was there and that he thought they might be able to see it during the day.

"Lambert," continued Peter, "ask Ben if he saw Van der Werf's portrait at the town hall last night?"

"No," said Lambert, "I can answer for him. It was too late to go in. I say, boys, it is really wonderful how much Ben knows. Why, he has told me a volume of Dutch history already. I'll wager he has the siege of Leyden at his tongue's end."

"His tongue must burn, then," interposed Ludwig, "for if Bilderdyk's account is true, it was a pretty hot affair."