500 L. A. Bauer — Wilde's Explication of the Secular 



with, dual foci of intensity coincident with the poles of the 

 earth's axis, and separate from the dual polar foci of the in- 

 ternal sphere of vapors." 



(3.) "The un symmetrical distribution of the magnetic ele- 

 ments arising from the unequal curvature and foldings of the 

 earth's crust during its secular cooling, as indicated by the 

 present distribution of land and water on the terrestrial sur- 

 face." 



He then seeks to embody his idea in a mechanism, which he 

 terms a Magnetarium and with it endeavors to demonstrate 

 the correctness of his theory. A brief description of it in its 

 final form is as follows : A plain, geographical globe, 16 inches 

 diameter, had wound round the whole of its surface insulated 

 copper wire, the winding beginning at the poles and ending at 

 the equator ; the terminals were then passed through the in- 

 terior and brought out at the poles, where they were joined 

 with the free ends. It was then mounted on capped axles, 

 cemented to opposite sides of the wired surface of the globe, 

 at an angular distance from the poles of at first 18°, but 

 changed finally to 23 - 5°, the polar distance of the poles of the 

 ecliptic. At these axles were the contrivances for establishing 

 permanent electrical connection with the generator of elec- 

 tricity, when the globe was made to revolve on its axis. This 

 represented the gaseous or electro-dynamic sphere. Then 

 another terrestrial globe, 18 inches diameter, was cut through 

 equatorially and the hemispheres mounted at the poles on 

 hollow axles, made to fit over the axles of the inner globe so 

 as to revolve separately and concentrically with it. These 

 hemispheres, to render them permanently magnetic, were 

 lined internally with iron wire gauze, covered with insulated 

 copper wire wound similarly to the inner globe, and were 

 magnetized by a branch of the current exciting the latter. 

 These two globes were then mounted on a fixed standard in 

 such a manner that any point up to latitude 72° could be 

 brought directly below the contrivance bearing specially con- 

 structed magnetic needles, two inches in length. The axles 

 were connected with an epicyclical train of wheels so that a 

 differential motion could be imparted to the globes such that 

 for a complete revolution of the former, the latter lost ^o °f a 

 revolution or 12°. The relative strength of the inner and 

 outer fields of force was adjusted by introduction of wire re- 

 sistances so that the point of vertical dip would be maintained 

 in latitude 72°, and the known maximum west declination and 

 inclination at London would be produced. By throwing the 

 wheels out of gear and moving the two spheres through the 

 same angle, the magnetic elements at all points of the globe 

 for the same epoch could be obtained. By turning the crank 



