Paper, 'On the relations of the secular variation of the magnetic declination and inclination at London, Cape of Good Hope [South Africa], St Helena and Ascension Island, as exhibited on the magnetarium' by Henry Wilde

Description

Wilde writes: 'In a paper which was read before the Royal Society in June, 1890 [see AP/80/6], I showed that the principal phenomena of terrestrial magnetism and the secular changes in its horizontal and vertical components could be explained on the assumption of an electro-dynamic substance (presumably liquid or gaseous) rotating within the crust of the earth in the plane of the ecliptic, and a little slower than the diurnal rotation. By means of some electro-mechanism, new to experimental science, which I termed a magnetarium, the period of backward rotation of the internal electro-dynamic sphere required for the secular variations of the magnetic elements on different parts of the earth’s surface was found to be 960 years, or 22.5 minutes of a degree annually. It was also demonstrated that the inclination of the axes of the electro-dynamic and terrestrial globes to each other of 20° 30', was the cause of the inequality of the declination periods about the same meridian in the northern and southern hemispheres; as instanced in the short period of outward westerly declination at London, and the long period of outward westerly declination at the Cape of Good Hope and St. Helena.'

Annotations in pencil and ink.

Subject: Magnetism

Received 19 February 1894 / 23 February 1894. Read 1 March 1894.

A version of this paper was published in volume 55 of the Proceedings of the Royal Society as 'On the relations of the secular variation of the magnetic declination and inclination at London, Cape of Good Hope, St. Helena and Ascension Island, as exhibited on the magnetarium'.

Reference number

PP/23/12

Earliest possible date

1894

Physical description

Ink and graphite pencil on paper

Page extent

11 pages

Format

Typescript