An American in London

A self-conceited American visited London, where he hired an Englishman to show him around the city.
"How long were they building that?" he asked his guide as they passed a large hotel.
"About six months, I think," answered the guide.
"Six months!" exclaimed the American. "It wouldn’t take us more than six weeks to build a hotel like that in New York."
They passed a building which was quite new.
"And how long were they building that?" asked the American.
"About four weeks," answered the guide.
"Four weeks!" exclaimed the American. "In New York we should build a house like that in six days."
Nothing more was said until they reached the Houses of Parliament.
"Well, that’s not a bad-looking place," said the American. "How long were they building that?"
"Well, you may not believe me," answered the guide, "but that building was not there when I crossed the bridge last night."