MILTON — Masons are working this summer to restore a century-old water tower on Middle Line Road owned by the town.

Milton received a $13,000 grant in 2005 from the state Office of Parks, Recreation and Historic Preservation for an engineering study of the stone tower and some of the physical work to shore it up. The balance of the project is being paid for by the town.

Town Historian Royann Blodgett said the old Rose Hill mansion water tower was used for about 60 years beginning in 1917.

The tower and land surrounding it were purchased in 2002 by the town at Blodgett’s urging.

“The work that’s being done now is meant to preserve the tower as well as to recognize it and show respect for the past,” she said. “It’s such an unusual structure.”

The property was once owned by Judge James Thompson, who was born in 1775. It is believed that it was his descendants who fed water from a nearby Plummer Road spring to the stone water tower.

John G. Waite Associates, an Albany architectural firm, conducted the study on how the tower could be preserved.

Three weeks ago, mason Matthew Tarbell, owner of Whitetail Stone Corp., in Granville, began working with Gary Clarke to fix the tower that had been falling apart.

“We’re starting our fourth week,” Tarbell said Monday afternoon. “I thought it would be a six- to eight-week job, but now I think it might take as long as nine weeks.”

He said frequent rain and thunderstorms have hampered the progress.

“The tower is 14 feet wide on each side and 16 feet tall,” he said. “We’re a little less than half done.”

He said they pulled the outer stones from the sides of the tower starting at ground level.

“The stones are heavy and the corner stones were probably made by the farmers. We’re pulling them out, drilling [between interior stones] and installing pins that are 12 to 18 inches long, which will anchor the stones as we put the veneer back on,” Tarbell said. “We’re also using authentic lime restoration mortar between the stones. We’ve needed more mortar than I anticipated.”

The men have completed all four sides to a height of about 7 feet in the project that’s drawing attention.

“We’ve had a number of people stop and ask questions as they’re biking or hitchhiking or on their motorcycles,” he said. “We’ve also had to stop a number of times and run for the truck when the thunder and lightning came through.”