I am reading The Great Gatsby, and came to wonder how the oil tank looked like in Wilson's garage.
With an effort Wilson left the shade and support of the doorway and, breathing hard, unscrewed the cap of the tank. In the sunlight his face was green.
"I didn't mean to interrupt your lunch," he said. "But I need money pretty bad, and I was wondering what you were going to do with your old car."
"How do you like this one?" inquired Tom. "I bought it last week."
"It's a nice yellow one," said Wilson, as he strained at the handle.
In this part, Gatsby and Daisy were driving to the town in Tom's blue car, and Tom, Nick and Jordan in Gatsby's yellow car. Because the gasoline was not enough in the yellow one, the latter group stopped at Wilson's garage to fill it up. At their order, Wilson screwed open the cap of the tank, which had the handle. Later in the text, it is found out that the tank also had a pump.
What I first imagined was a small, handy oil tank, which you could pick up and tilt. But later I found out that it also had a pump, so I was confused as to how the oil tank looked like in the 1920s.