British scientist and Unitarian theologian Joseph Priestley used this brass-and-glass telescope in his laboratory at his home in Northumberland County, Pa. Selected by CAP Curator Jennifer Gleim as this week’s Pennsylvania Treasure, the telescope, on loan from the Joseph Priestley House, is featured in The State Museum’s Pennsylvania Icons exhibit.
The earliest known working telescopes appeared in Europe in the early 1600s and consisted of convex and concave lenses inside a tube. These rudimentary devices magnified objects by three-to-four times their normal size. Over the next 200 years many scientists including Johannes Kepler, Galileo Galilei, Isaac Newton and John Hadley contributed significant scientific advancements to the telescope’s design, greatly improving its functionality. As glassmaking techniques improved, so too did the clarity and quality of the lenses used in telescopes.
By the 1790s, when Joseph Priestley’s telescope was most likely manufactured, scientists were able to use telescopes to accurately observe and measure the positions and movements of the stars.
Born in 1733, Joseph Priestley immigrated to Pennsylvania from England in 1794. He sought to escape the hostility from his countrymen that culminated in the destruction of Priestley’s home and laboratory in response to his controversial religious and political views. Around 1798, Priestley constructed a home and laboratory in Northumberland, Northumberland County.
Priestley was a supporter of both the American and French revolutions and an advocate for religious freedom. He received his education as a minister at Daventry Academy, an institution established by English Dissenters, a group of Christians who rejected the Church of England and opposed government interference in religious matters. Priestley spent much of his adult life working in the ministry, teaching and publishing theological works. His studies in theology led him to assist in the founding of the Unitarian Church in England as well as helping to establish the first Unitarian Church in America, in Philadelphia.
Receiving little formal education in the sciences, Priestley was encouraged by his friend, Benjamin Franklin, to begin studying the effects of electricity. His most notable scientific work, however, came from his study of gases. Priestley’s first publication related to chemicals was a description of how to carbonate water. In 1774, he isolated the gas that would come to be known as oxygen at a laboratory in Wiltshire, England.
Joseph Priestley also made groundbreaking observations regarding the process of photosynthesis and discovered that India rubber would remove pencil markings. From the laboratory in his Northumberland home, he isolated carbon monoxide and published more than 30 scientific papers.
Joseph Priestley died on Feb. 6, 1804 and is buried at Riverview Cemetery in Northumberland.
About Pennsylvania Icons:
Featuring a diverse array of artifacts from the collections of the State Museum of Pennsylvania and other Pennsylvania Historical and Museum Commission historic sites and museums, Pennsylvania Icons tells the story of our commonwealth, its people and the role they played in shaping the nation. The exhibit features historic artifacts ranging from a 1654 map of the Philadelphia region to pieces of the Walnut Street bridge in Harrisburg. Pennsylvania Icons opens to the public on Sunday, November 8, 2015.
About Pennsylvania Treasures:
In early 2012, The Pennsylvania Historical and Museum Commission launched the Collections Advancement Project (CAP), a program to inventory and catalog our vast and significant holdings of art and artifacts. These efforts are resulting in better stewardship of our collections which represent Pennsylvania arts, culture, history, sciences, business and agriculture. As a component of the project, CAP curators have researched rarely exhibited artifacts and works of art. We are sharing these Pennsylvania Treasures with the public through weekly updates.