ROCKFORD - A rare piece of history will be on display this weekend at the Cedar Valley Engine Club Thresher Reunion in Floyd County.

An authentic 1797 James Watt steam engine will star Saturday through Monday. The event will be seven miles west of Charles City at the intersection of Iowa highways 14 and 147.

The Cedar Valley Engine Club acquired the stationary engine - formerly part of a collection of steam tools at the Do-All Co. museum in Des Plaines, Ill. - a little more than a year ago.

"It's part of history that you won't see anywhere else," said Michael Shanks of Nora Springs, a club director.

The James Watt is believed the oldest steam engine west of the Mississippi River. It was used to power a textile mill in Chard, England, for 140 years and was built at the Boulten and Watt Factory in Birmingham, England.

The 60-horse engine operated on five pounds of steam pressure. When it was purchased and brought to the United States in 1958, the engine was still operational.

Eleven club members went to Chicago to inspect the engine in the spring of 2005. They disassembled the machine for the move to Iowa, a process that required 10 days, Shanks said, because the workers took careful measurements and tagged parts.

The craftsmanship in the engine is outstanding, according to club members.

The largest engine components are the walking beam, connecting rod and steam cylinder. The teeth on the two-part crank gear are made of wood.

Last September, club members dug a basement for the engine at the Thresher Reunion show grounds. They plan to build an enclosure around the antique.

"Eventually, we're going to hook an electric motor on it so people can see how it works," Shanks said.

With handmade parts, including precisely placed bearings, the engine required several months to assemble, he said. The process was completed this week.

"To think that they could make castings and pour iron that weighed tons back then, and for us to be able to work on something that is 200 years old and put it back together again, is just fun," Shanks said.

Contact Kristin Buehner at (641) 421-0533 or kristin.buehner@globegazette.com.