They can be made, too, to cover in any extent of area without sustaining walls.
After he had educated himself by the study of the phenomena of lines of magnetic force in his discoveries on electromagnetic induction, he applied the same conception to electrostatic phenomena, and thus created the notion of lines of electrostatic force and of the important function of the dielectric or non-conductor in sustaining them.
Their sustaining power has been calculated at 2016 tons, while the whole weight of the suspended part of the bridge is only 489 tons.
Another and very obvious difficulty is traceable to the great disparity in the weight of air as compared with any known solid, and the consequent want of buoying or sustaining power which that disparity involves.
By doing this they are protecting natural populations in the forest, sustaining biological diversity in vivo.