Not all the towers along a transmission line are identical. Look closely at a tower where the line makes a sharp turn and you will likely find it is wider and beefier than other towers along the route. The added strength and weight are needed to resist the unbalanced pull of the conductors, which might overturn an ordinary tower. These special towers are called deviation or angle towers.
The transmission-line tower everybody knows is an Erector Set latticework of steel girders and diagonal braces. The techniques for designing and building these towers are the same ones used in constructing steel bridge trusses or crane booms. The individual pieces can be made cheaply from rolled steel and then bolted together on the site. This last point is more important than it might seem: transporting a fully assembled tower 100 feet tall is an awkward and expensive business.
When poet William Blake wrote of "dark satanic mills", he couldn't have been looking at a steel mill because there were none in 1804. Nevertheless, when I visit a steel mill, Blake's phrase always comes to mind. With the heat and the pounding noise, the dust and smoke, and the red glow against the night sky, it's hard not to see these places as infernal. And yet the process of making steel also produces some of the most hauntingly beautiful images found anywhere in the world of industry.
It is so easy to fall into the trap of contemplating a city’s uses one at a time, by categories. Indeed, just this—analysis of cities, use by use—has become a customary planning tactic. The findings on various categories of use are then put together into “broad, overall pictures.”
The overall pictures such methods yield are about as useful as the picture assembled by the blind men who felt the elephant and pooled their findings. The elephant lumbered on, oblivious to the notion that he was a leaf, a snake, a wall, tree trunks and a rope all somehow stuck together.