Variations
On the magnet, magnetick bodies also, and on the great magnet the earth: a new physiology, demonstrated by many arguments & experiments
Variation
Chapter 1
The variation is caused by the inæquality of the projecting parts of the Earth
Chapter 2
The variation in any one place is constant.
Chapter 3
Variation and direction arise from the disponent power of the earth
Chapter 6
The construction of the common mariners' compass
Chapter 8
Can the terrestrial longitude be found from the variation?
Chapter 9
The finding of the amount of variation
Chapter 12
Why do the Observations of variation by seamen vary and uncertain?
Chapter 13
The variation of the magnetick needle in the great Æthiopic and American sea, beyond the æquator.
Chapter 15
The variation in the interior of large Continents.
Chapter 19