‎"KATER, HENRY. - ESTIMATING THE ELLIPTICITY OF THE EARTH.‎
‎An account of experiments for determining the ariation in the lenght of the pendulum vibrating seconds, at the principal stations of the Trigonometrical Survey of Great Britain. Read June 24, 1819.‎

‎London, W. Bulmer & Co., 1819. 4to. No wrappers as issued in ""Philosophical Transactions of the Royal Society of London for the Year MDCCCXIX."", Part III. With titlepage to Part III. (4), pp. 337-508. Clean and fine.‎

Reference : 46536

‎First appearance of Kater's great paper, a report of his results as member of ""The Survey of Great Britain"", using his invention, ""Kater's Pendulum"".""On the basis of the principle enunciated by Huygens that the centers of suspension and oscillation are interchangeable, Kater devised a reversible pendulum (which became known as ""Kater’s pendulum"") with knife edges accurately adjusted to lie at the conjugate points. By using the distance between these points as the ""length"" in the formula for a simple pendulum, he was able to determine with great accuracy the length of a pendulum beating seconds under specified conditions. He thereby obtained accurate values for g, the acceleration due to gravity, at several stations of the Trigonometrical Survey of Great Britain and estimated the ellipticity of the earth. Kater performed these experiments as a member of a committee appointed by the Royal Society in response to a request by the governmnet for assistance in standardizing weights and measures.""(DSB).‎