Words can't describe it, but the visitors try: "Breathtaking." "Amazing." "Extraordinary."
They're at Sotheby's where they are gazing on the life's work of Jerry Green.
One look will convince you that there is such a thing as a collecting gene, and that Jerry Green inherited it.
For nearly fifty years, Green has been accumulating model trains and the paraphernalia that goes with them.
"All of these trains were manufactured by a company called Bing," he said. "I believe they went in business around 1860 or 1866; they stayed in business up until 1933.
"I eventually collected every accessory and station that Bing had made, from when they went into business until they went out of business."
"That's how many pieces, you think?" asked Teichner.
"Over a thousand."
Oh, but there's more, lots more. Green showed Teichner train stations manufactured by Marklin, which he called "the Rolls Royces of the toy industry."
"These were the finest, the best pieces, they were all hand-crafted, and each one is different. They made over 150, which I have."
When Green decided to sell the collection, it took his entire family three weeks to unpack and arrange what was on display at the auctioneers, Sotheby's in New York.
Believe it or not, this was only a small portion of what he has.
"The Greens kept bringing more and more boxes . . . and boxes . . . and boxes ...
David Redden, vice chairman of Sotheby's, believes it's the biggest train collection in the world.
"He didn't realize what he had, because he just assumed there were just a lot of other closet collectors like him," said Melissa.
"Basement collectors," actually. Jerry Green bought his house outside Philadelphia because it had a 5,400-square foot basement. Eighty percent of the collection is still there.
He says he has more than 1,700 locomotives and cars, 700 stations, and thousands of accessories.
"In cataloguing the collection, I came up with 27,000 different items," he said. "And I probably had another ten thousand" to catalog.
He admits he's an "obsessive collector."
The trains were for fun. But Green never really played with them much. And he kept them a secret from other collectors, just quietly buying all of it one piece at a time.
"The excitement was in finding it," he said. "All the manufacturers always put out catalogues. And I'd circle what I'd need, and then when I got it, I would put an X through it, and I just tried to collect everything that these companies made."
When he had just about every train Lionel ever made, he sold them all, and began acquiring European trains and accessories, dating from about 1850 through the 1930s.
Here, in miniature, are perfect replicas of a vanished age, like a miniature of a bridge designed by Eiffel (as is Eiffel Tower) c. 1908. The real bridge existed in Germany, up until the First World War. "And it was bombed out," said Green.
The real bridge is gone. The toy version remains.
Jerry Green decided to sell the collection when he ran out of good pieces to buy. How much is it worth?
Here's a hint . . .
Green described one station that went to auction for a six-figure sum: "I know of two other copies of this station that exist; a German collector has one, and one recently sold for $140,000."
And that's just one station. Sotheby's intends to sell everything . . . to a single buyer.
"Do you have any inkling of what would be a minimum price?" Teichner asked.
"I have some inkling," Redden said. "Well into eight figures."
"So that would be above ten million?"
"Well above ten million."
Jerry Green's son, Michael, collects nothing. But neither he nor his sisters can keep from fussing with the displays at Sotheby's.
"When we first came up to Sotheby's the first day, we wanted to get sleeping bags and sleep over - we couldn't imagine leaving, because it's always been in our basement, and we didn't wanna leave it."
They all admit they'll miss the trains.
"It's so much a part of our relationship with our father that it'll be weird to not be there," said his daughter Melissa. "I can't even imagine."
But for Jerry Green himself, it's "been there, done that." He's ready to move on.
"I definitely will collect something else," he said.
"Can you imagine spending the time, and the money, and the effort and so on, and filling up these rooms all over again?" asked Teichner.
"Absolutely! I'm a collector," he replied. "I would have to. That's the fun."