Ongoing Work on the
Hartness Turret Telescope

by Dave Groski, Springfield Telescope Makers

Photos by Matt Considine and Bert Willard

Dave Groski and Jim Daley inspect the lens of the Hartness turret before removing it.

In August, 2012, a few days before Stellafane Bert Willard, Jim Daley, Matt Considine and I noticed what looked like a couple of small chips on the edge of the objective lens of the Hartness turret telescope that we didn't remember seeing before. Jim had to leave and he was the only one that had any knowledge of how the cell held the elements in place. We decided to wait until I could come back up in October so we could regroup to tackle the job of removing the objective and separating the elements from the cell to see what was going on. We all had nightmares of corroded parts in dealing with taking the cell apart. So we showed up on October 13th with all kind of penetrating oils, and tools. Luckily that wasn't the case and the screws easily came out along with the front retainer ring (which is not threaded but held in place by the three screws). It looks like water had some how got into a corner of the cell and froze. That caused three small chips in the flint element of the 10-inch Brashear  objective. We gave the elements a bath, Jim stoned the chips, reassembled the objective and sealed the cell to stop any water leaks.

Dave Groski removes the brass retaining ring, held on with three screws.

Over the last two years Jim, Bert, Matt and myself have repaired a number of issues with the Turret and cleaned it up. I painted the floor and observing platform back in August. Beside the objective cleaning, we also added a small light bulb to warm the prism to help keep it dry and a small bag of moth balls inside the the tube to keep the bugs out which has been a real problem. The scope has been used a couple of times for observing and we are pleased to report, it is working well. We have plans for additional improvements and repair in the Spring such as adding battery-powered red LED lights to illuminate the setting circles, stairs and observing platform and renumbering the declination circle were the painted numerals have faded.

The last couple of year (2011 and 2012), observing has been done with the Hartness turret after the Hartness House Workshop held on the Thursday of convention. The continuing improvements will make this historic intrument better than ever and provide an enjoyable view for our Thursday evening guests.

With the lens removed from the cell, Dave points to a chip and Bert leans in to get a good look.	Dave scrubs corrosion off the inside of the lens cell.	Jim Daley holds the flint lens element - a chip in the edge is quite evident.
Dave Growski gives the crown element a bath.	Jim Daley and Bert Willard do a final cleaning on the crown, while Dave Groski watches.	Jim Daley stones the flint chips, to remove stress and prevent them from spreading.
Dave Groski & Jim Daley reassemble the lens. All the work was done in our underground ATM museum.	Dave, Jim and Matt are reattaching the objective lens in its cell to the telescope tube.	Dave Groski, Jim Daley and Matt Considine give this project a triple thumbs-up.

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