Cornell University - just south of Campus Road, located outside the Engineering Department in the Engineering Quad
Description:
This 650 pound equatorial has a gear adjustment to rotate the equatorial time ring using a knob on the side of the pillar. This allows correction for the Equation of Time (sun's apparent variability in crossing the noon meridian and enables the instrument to read clock time, making this a very precise instrument. The gearing rusted in 1980 and was refurbished: "The heart of the sundial's functionality, a roundish steel disc called a cam, was also replaced with a stainless steel, slightly better-functioning one, connected to an hour and minute scale by small, stainless steel cables via a pair of precisely designed pulleys." Thus the mechanical adjustment compensates for the sun's irregular motion called the Equation of Time and shows civil not solar time.
Dale R. Corson, physicist and engineer, and eighth president of Cornell University, built the sundial in 1980. "This is my legacy to Cornell," Corson said. He shares credit for the dial's design with Professor Emeritus Richard Phelan, who created the mechanism in its base that allows the equatorial ring to rotate and show correct civil time.
The equatorial ring is delineated at one minute intervals allowing the shadow of a thin gnomon to show the advancing of time. The gearing mechanism is set to the date and provides both Equation of Time and longitude corrections. In 2006 the dial was refurbished by Corson and Rodney Bowman, a scientific instrument maker on campus who upgraded the cam and gearing. From the Cornell alumni website: “Dale was about ninety years old at the time,” recalls Stanley Carpenter, who managed the machine shop until his retirement in 2009. “But working on this project, he was as enthusiastic as a freshman.” The original cam had rusted over the previous 26 years—so the pair made the replacement out of corrosion-resistant stainless steel. “Considering the weather in Ithaca,” says Carpenter, “this was a huge improvement.”
General Information:
Inscription:
Owner: Cornell University
Inscription on the dial base:
"The Joseph N. Pew, Jr. Sundial
Designed and Erected
In Memory of His Loyalty to
Engineering at Cornell"
The dial was inspired by Pew's widow who thought it a fitting memorial for her husband.
Designer: Dale R. Corson
Builder: Richard Phelan (maker of the EOT adjustment cam)
Cornell University Sundial - CornelliansOct 2021.pdf 4884.889 KBytes
