Rings from the Qing dynasty (1644-1911) were round cylinders or D-shaped cylinders.

A pause; then Grant said, "The pipe goes into a round black cylinder that looks like a fuel pump."

At first glance he was disappointed by its simplicity, a fat, round cylinder, with a smaller pipe attached to its side.

He reached in again and grabbed a round cylinder.

It was standing on its own, a great round cylinder extending down through the clouds, supported by no visible means.

The piston sealing problem was due to having no way to produce a sufficiently round cylinder.

Another demonstration is to direct the air flow from, e.g., a vacuum cleaner operating in reverse, tangentially past a round cylinder.

Towering round cylinders encased in mirrored glass, these buildings evoked silos from which missiles might momentarily erupt.

"These pistons are round cylinders?"

Round dual run capacitors (shaped as round cylinders) are commonly used for air conditioning, to help in the starting of the compressor and the condenser fan motor.