(isodynamic), equal inclination (isoclinic), and equal deviation (isogonic).
Position of the magnetic pole. Its probable connection with the poles of
cold. Change of all the magnetic phenomena of the earth. Erection of
magnetic observatories
p 19
since 1828; a far-extending net-work of magnetic stations -- p. 190 and
note. Development of light at the magnetic poles; terrestrial light as a
consequence of the electro-magnetic activity of our planet. Elevation of
polar light. Whether magnetic storms are accompanied by noise. Connection
of polar light (an electro-magnetic development of light) with the formation
of cirrus clouds. Other examples of the generation of terrestrial light --
p. 202 and note.

b. The vital activity of a planet manifested from within outward, the
principal source of geognostic phenomena. Connection between merely dynamic
concussions or the upheaval of whole portions of the earth's crust,
accompanied by the effusion of matter, and the generation of gaseous and
liquid fluids, of hot mud and fused earths, which solidify into rocks.
Volcanic action, in the most general conception of the idea, is the reaction
of the interior of a planet on its outer surface. Earthquakes. Extent of
the circles of commotion and their gradual increase. Whether there exists
any connection between the changes in terrestrial magnetism and the
processes of the atmosphere. Noises, subterranean thunder without any
perceptible concussion. The rocks which modify the propagation of the waves
of concussion. Upheavals; eruption of water, hot steam, mud mofettes,
smoke, and flame during an earthquake -- p. 202-218 and notes.

c. Closer consideration of material products as a consequence of internal
planetary activity. There rise from the depths of the earth, through
fissures and cones of eruption, various gases, liquid fluids (pure or