graphics3d - How I calculate the volume of multiple intersecting spheres?

I would like to know how to calculate the volume of the union of multiple possibly intersecting spheres (using Sphere[]). Please see the figure:

enter image description here

I was trying to get a mesh/delaunayMesh out of the spheres and apply "Volume" which didn't work.

Edit: Fixed spelling (Feb 6th).

Answer

spheres = {
   Sphere[{50, 50, 50}, 25],
   Sphere[{70, 70, 70}, 25]};


rgn = RegionUnion @@
   (spheres /. Sphere -> Ball);

RegionMeasure[rgn // N]

122585.

Volume[rgn // N]

122585.

EDIT: Example with more elements

rgn2 = RegionUnion[
   Ball[{100., 100., 100.}, 30.], Ball[{120., 120., 120.}, 30.], 
   Ball[{130., 130., 130.}, 30.], Ball[{140., 140., 140.}, 30.], 
   Ball[{190., 190., 190.}, 30.], Ball[{200., 200., 200.}, 30.], 
   Ball[{210., 210., 210.}, 30.], Ball[{230., 230., 230.}, 30.]];


RegionMeasure[rgn2]

590768.

Volume[rgn2]

590768.

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