Not sure this is the site to ask this question, but here it goes anyway:
The other day I saw an electricity cable hanging in an unusually wide curve. That got my attention and I looked out of the window to find out that that cable was in the process of installation by two guys on top of two very high apartment buildings about 70 meters away from each other. There were no cranes in vicinity, so naturally I started wondering how in the world they got one end of the cable to the other roof. It isn't likely that one guy just threw a cable's end to the other guy. How is this done in cities without the use of cranes?