"Look!" screamed Ben. "There IS a white cushion at the door of that double-joined house with the funny roof."

"I don't see any house with a funny roof."

"Oh, of course not," said Ben. "I forgot you're a native, but all the roofs are queer to me, for that matter. I mean the house next to that green building."

"True enough, there's a girl! I tell you what, captain," called out Lambert, slipping easily into Dutch, "we must get out of this street as soon as possible. It's full of babies! They'll set up a squall in a moment."

The captain laughed. "I shall take you to hear better music than that," he said. "We are just in time to hear the organ of Saint Bavon. The church is open today."

"What, the great Haarlem organ?" asked Ben. "That will be a treat indeed. I have often read of it, with its tremendous pipes, and its vox humana *{An organ stop which produces an effect resembling the human voice.} that sounds like a giant singing."

"The same," answered Lambert van Mounen.

Peter was right. The church was open, though not for religious services. Someone was playing upon the organ. As the boys entered, a swell of sound rushed forth to meet them. It seemed to bear them, one by one, into the shadows of the building.