Lecture On The Pendulum-Experiments At Harton Pit: Delivered In The Central Hall, South Shields, October 24, 854 - Softcover

George Biddell Airy

Softcover

ISBN 10: 0461853868 ISBN 13: 9780461853865

Publisher: HardPress, 1854

Synopsis

Lecture On The Pendulum-Experiments At Harton Pit: Delivered In The Central Hall, South Shields, October 24, 854 — George Biddell Airy. This work presents Airy’s account of the pendulum experiments conducted at Harton Pit to probe the Earth's density by descending deep into a coal mine. It situates the study within the broader lineage of gravitation research, tracing how pendulums can reveal the variation of gravity with depth and how such measurements contribute to weighing the Earth. The text explains the theoretical framework: how planetary motions and inverse-square gravity relate to masses, and how observations from mines and mountains have historically informed Earth density. It then outlines the experimental program: selecting two stations near Harton Colliery, building a fortified observation chamber, and using detached pendulums whose vibrations are counted by a clock pendulum via a coincidence method with a light-discs and telescopes. The apparatus includes careful temperature, air-density, and buoyancy corrections, galvanic clock synchronization, and repeated pendulum interchanges to control systematic errors. The narrative culminates with the presentation of results and an accompanying letter from the Royal Observatory, confirming gravity’s slight increase with depth and offering a quantitative density relation for the shell relative to the inner sphere.

Edition details

• Publisher: HardPress
• Publication date: 1854
• Language: English
• ISBN 10: 0461853868
• ISBN 13: 9780461853865
• Binding: Paperback
• Number of pages: 40