On the Means Adopted in the British Colonial Magnetic Observatories, for Determining the Absolute Values, Secular Change, and Annual Variation of the Terrestrial Magnetic Force.
London: Taylor, 1850. From the Philosophical Transactions - Part I, for 1850. Slim 4to 19 pages (pp. 201- 219). modern wrappers. London: Taylor, 1850. Overall a very good copy. More