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.
But the coppersmiths themselves, in their desire to do better or otherwise than their predecessors, soon quit the line of truth and propriety. There comes then a second coppersmith, who proposes to modify the form of the primitive vase in order to seduce the purchaser with the attraction of novelty...and it becomes fashionable, and everybody in town must have one of the vases made by the second coppersmith. A third, seeing the success of this expedient, goes still further, and makes a third vase, with rounder outlines, for anybody who will buy it. Having quite lost sight of the principle, he becomes capricious and fanciful...yet everyone applauds the new vase, and the third coppersmith is regarded as having singularly perfected his art, while in fact he has only robbed the original work of all its style, and produced an object which is really ugly and comparatively inconvenient.