When a new medium borrows from an existing one, some of what it borrows makes sense, but much of the borrowing is thoughtless, “ritual,” and often constrains the new medium. Over time, the new medium develops its own conventions, throwing off existing conventions that don’t make sense.
If you ever get the chance to watch early television drama you’ll find a strong example of this. Because radio required a voice-over to describe what listeners couldn’t see, early television drama often featured a voice over, describing what viewers could. It’s a simple but striking example of what happens when a new medium develops out of an existing one.
An exclusive, behind-the-scenes look at the genius of Japan's foremost living film director, Hayao Miyazaki — creator of some of the world's most iconic and enduring anime feature films.
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.