Posts Tagged sir john bennett
Shoulder Surgery: Replication of Magog’s Arm
The Sir John Bennett tower clock. / Photo by The Henry Ford. / THF53988
The quarter-hour chime of the Sir John Bennett tower clock is a memorable sound that can be heard throughout Greenfield Village, emanating from its four figures—the muse, Gog, Magog, and Father Time (shown right to left above). Early in 2021, Magog’s chime and striking arm developed cracks along the mechanical shoulder.
Recorded damage of Magog’s chiming arm. / Photo by Andrew Ganem.
Disassembly of Magog’s arm prior to cleaning. / Photo by Andrew Ganem.
The arm was disassembled by Conservation Specialist Andrew Ganem, and conservation and curatorial staff were faced with a decision to repair the original arm or to replace it with a replica. One of the major concerns with repair was that new cracks could develop in the already thin (0.04”) sheet metal when Sir John Bennett becomes operable again. After some discussion, we made a decision to replicate and replace the arm to allow for safe operation of the clock, while preserving the original component in storage for future reference.
The replica arm could not be easily replicated using conventional copper metalwork techniques because of its highly textured surface. An easier replication method came from our partners at Ford Motor Company, who proposed the use of 3D scanning and polymer printing. To accomplish this, the original arm was 3D scanned and that data imported into a computer-aided design (CAD) program. The replica arm was then printed using stereolithography (SLA) 3D printing. You can learn more about this type of printing here.
Image courtesy Ford Motor Company.
Image courtesy Ford Motor Company.
Image courtesy Ford Motor Company.
The scanned model of the arm was produced by Daniel Johnson and Kevin Lesperance at Ford Motor Company’s metrology lab.
A side-by-side comparison between the SLA 3D-printed copy on the left and the original artifact on the right. / Photo by Cuong Nguyen.
The 3D-printed part is tested for fit prior to electroplating by Ford Motor Company’s Erik Riha on left and The Henry Ford’s Andrew Ganem on the right. / Photo by Cuong Nguyen.
The SLA plastic material wasn’t strong enough to endure continuous use in the outdoor environment of Sir John Bennett’s tower clock, so Ford engineers proposed coating the replica polymer part with nickel and copper layers using electrical deposition. The nickel layer stiffened the print, while the copper layer offered a better surface for painting.
Test for fitting the plated arm onto Magog. / Photo by Cuong Nguyen.
Holes in the cast iron mount for the arm. / Photo by Cuong Nguyen.
The use of an appropriate painting system that could endure the outdoor environment in Greenfield Village was imperative. Dr. Mark Nichols of Coatings, Surface Engineering, and Process Modeling Research at Ford Motor Company and Dan Corum of PPG recommended PSX-One (high solids, acrylic polysiloxane.) Amercoat 2/400 was used as a primer, as it provides chemical, environmental, and moisture resistance. The paint colors on the original arm were matched to a color sample and duplicated by Andrew Wojtowicz of PPG.
Original arm, left; 3D-printed arm, right; and Munsell color sample in the middle. / Photo by Cuong Nguyen.
The primed surface on the shoulder and elbow was coated with oil sizing and gilded with 24-karat gold.
Left to right: SLA-printed replica; copper/nickel/copper-plated SLA replica; copper/nickel/copper-plated SLA replica primed, painted, and gilded, ready for use; and original artifact part for comparison. / Photo by Cuong Nguyen.
During a test assembly, we noted that the linkage that connects Magog’s arm to the chiming mechanism was too short, so Andrew fabricated an extension and attached it to the original linkage. He also fabricated new hardware for the elbow joint to accommodate the additional thickness of the replacement part.
Extension fabricated by Andrew Ganem. / Photo by Andrew Ganem.
Photo by Cuong Nguyen.
Elbow joint. / Photo by Cuong Nguyen.
Original and machined hardware. / Photo by Andrew Ganem.
Magog’s clapper for the bell striker required attention by Andrew and The Henry Ford’s welder Chuck Albright, who soldered the joint between the cuff, wrist, and grip for the strike (hammer). A vibration isolator (made from Sorbothane) was inserted to reduce shock between the clapper and the arm during operation.
Separation between the hand and the wrist. / Photo by Cuong Nguyen.
Required surface preparation for a strong solder repair. / Photo by Andrew Ganem.
The size of the fist. / Photo by Andrew Ganem.
Special thanks to Dr. Mark Nichols, Dr. George Luckey, Erik Riha, Daniel Johnson, and Kevin Lesperance at Ford Motor Company, and to Daniel Corum and Andrew Wojtowicz at PPG. The help from Ford Motor Company specialists and their fabrication equipment made the project possible without invasive modifications to the artifact part.
We also extend a grateful thank you to Jason Hayburn, whose generous donation funded the electroforming of the replica.
Cuong T. Nguyen is Objects Conservator at The Henry Ford.
Michigan, Dearborn, 21st century, 2020s, technology, Sir John Bennett, philanthropy, Greenfield Village buildings, Greenfield Village, Ford workers, Ford Motor Company, conservation, collections care, by Cuong Nguyen, #Behind The Scenes @ The Henry Ford
Restoring Sir John Bennett's Giants
Sir John Bennett. / THF17783
For decades, Sir John Bennett's shop—with its figures of mythological giants Gog and Magog—has intrigued and enthralled Greenfield Village's visitors. Prior to 1930, the jewelry and clock shop was a popular presence many thousands of miles away in London, where its animated giants chimed the quarter-hours above the busy thoroughfare of Cheapside.
While London and Dearborn would seem to have little in common, Gog and Magog—if they could talk, as well as chime—might disagree. Exposure to the weather has been a continuous element in their over 125 years of timekeeping in both England and America. Climate has taken its toll on the figures. So, during the winter of 2005–2006, The Henry Ford undertook an extensive restoration of the Sir John Bennett figures.
This was not the first time that the figures, or "jacks," as they are known in the world of clocks, had been given a thorough restoration. When Henry Ford originally brought them to the United States in 1931, he had them repaired and repainted. A second restoration and repainting took place in the 1970s.
Pre-restoration deterioration on the feet of one of the carved wooden figures.
The 2005–2006 restoration, in addition to reversing damage and safeguarding Gog and Magog for future generations, also offered an opportunity to attempt to determine what the wooden figures originally looked like. Deeply carved recesses were carefully excavated in order to discover clues to the original color scheme. Conservators also studied a similar set of Gog and Magog figures in London's Guildhall; a set in Melbourne, Australia; and many historical prints and illustrations to compare our paint analysis with other known examples.
One finding was that the giants' chain mail had, at some point, been painted the color of their clothing. The chain mail is now painted to look like metal rather than cloth. Areas of the giants' armor were found to have traces of gold leaf in the recesses. Also, successive paint layers and weathering had obscured a number of decorative elements in the giants' armor. Previous restorations had used gold-colored paint on the armor, which eventually oxidized and turned brown. In 2005–2006, all the decorative armor components were coated with gold leaf.
The figures themselves were in poor structural condition, with many breaks and numerous large cracks. With a view to preserving as much of the original figures as possible, the decision was made to inject a deep penetrating resin into the porous wood, rather than cut out and replace damaged sections.
Newly restored Gog and Magog await their return to the Sir John Bennett shop.
Of course, Gog and Magog are not the only figures in the facade of the building—Father Time and a Muse are also in attendance to assist in the job of chiming. Made of plaster rather than wood, these figures were given structural repairs and then gilded with 1,400 sheets of gold leaf. During the repair work on the Muse, decorative elements were discovered on the harp under layers of paint and filler. The decoration was carefully restored, and can be seen on the front vertical post of the harp. A maker's name, "Brogiotti," was also revealed during the restoration.
Finally, the internal mechanisms for all four figures were repaired, and additional lubrication points were added to help minimize future wear.
Father Time and the Muse show off their new coats of gold leaf.
The clock mechanism was in need of a complete overhaul. Many of the bronze bearings—separate components fitted into the clock movement's large cast iron frame—had become worn and needed to be "re-bushed" to bring the mechanism back to its original operating specifications. During cleaning, conservators discovered that all of the cast iron framing was originally painted a blue-green with white pin striping. All of this original paint was carefully cleaned and preserved.
Conservator Malcolm Collum reassembles the restored Sir John Bennett clock movement.
During the 1931 reconstruction of the building and clock in Greenfield Village, a number of components were replaced. Cleaning the mechanism helped us gain a better understanding of the extent of Henry Ford's restoration: the modern steel components lack the dark graining found in the original wrought iron pieces. These dark lines are called "slag inclusions," remnants of a glass-like material that gets worked into the iron during the smelting and production processes.
Gog and Magog receive the most attention from visitors—understandably, given their size, character, and animation—but higher up, fully exposed to everything the Michigan climate has to offer, is one of the most vivid elements of Sir John Bennett's shop: the dragon weathervane. The dragon—made of hammered copper and detailed with sharp claws, taut bat-like wings and a fiery tongue—is a quiet masterpiece of design, craftsmanship, and balance. Its swept-back wings and extended tail are designed to catch even the slightest breeze; its head is weighted with lead in order to balance the body and allow for free pivoting.
The dragon weathervane is readied for removal from its perch.
When the dragon was removed from its perch in late 2005, it was found to be in stable condition. Structural repairs were followed by a thorough cleaning to remove corrosion and degraded metallic paint. Finally, rather than simply repaint the dragon, we returned it to its original splendor with a coat of gold leaf.
Dragon weathervane during gilding.
Repaired and resplendent, silhouetted against a Dearborn rather than a London sky, the dragon once again watches over the visitors who gather to watch Gog and Magog.
Malcolm Collum is former Conservator at The Henry Ford and Marc Greuther is Chief Curator and Vice President, Historical Resources, at The Henry Ford. This post originally ran as part of our Pic of the Month series in May 2006.
Michigan, Dearborn, Europe, 21st century, 2000s, Sir John Bennett, research, Greenfield Village buildings, Greenfield Village, conservation, collections care, by Marc Greuther, by Malcolm Collum, art, #Behind The Scenes @ The Henry Ford
Many people are familiar with the numerous literary connections at Greenfield Village: poet Robert Frost, lexicographer Noah Webster, and textbook author William Holmes McGuffey. But a little known literary relationship is that between Sir John Bennett, a clock and watchmaker and jeweler--whose storefront was moved from London, England to Greenfield Village in 1931--and one of his most prestigious customers, author Charles Dickens. Continue Reading
1860s, 1850s, Europe, 19th century, Sir John Bennett, Greenfield Village buildings, Greenfield Village, by James Moffet, books